Occurrence, distribution and sources of bisphenol analogues in a shallow Chinese freshwater lake (Taihu Lake): Implications for ecological and human health risk

A novel electropolymerized molecularly imprinted dual-mode sensor for bisphenol AF detection in pond mud

Recently, bisphenol AF (BPAF) as most commonly used bisphenol A analogs had the increasing higher level in the environment with unknown risks. Herein, a synchronous dual-mode sensor had been established based on differential pulse voltammetry (DPV) and electrochemiluminescence (ECL) for the detection of BPAF in pond mud. Firstly, the sensing molecularly imprinted polymer (MIP) films were prepared by electrochemical polymerization procedure with 3,4-ethoxylene dioxy thiophene (EDOT) as the functional monomer, BPAF as the template molecule and MXene as the supporting electrolyte. Due to unique characters of PEDOT and MXene, the constructed MIP films were stable and highly conductive. Meanwhile, zinc-doped bismuth sulfide quantum dots (Zn-Bi2S3 QDs) were synthesized as a nano-emitter to generate strong ECL signals in the MIP film. In the sensing process, a pulsed voltage applied to the PEDOT/MXene MIP film to generate both DPV and ECL signals for simultaneous dual-mode detection. Additionally, the liquid-liquid extraction with deep eutectic solvent (menthol: octanol 1:1) was used for the pre-concentration of the BPAF in the pond mud. Based on the sensing system, the ECL and DPV response showed the good linear relationships with the concentration of BPAF with the ranges of 0.01 μM-50 μM and 0.1 μM-50 μM and the detection limits of 0.0060 μM and 0.059 μM, respectively.

Transcriptomic analysis reveals the effects of maternal exposure to bisphenol AF on hypothalamic development in male neonatal mice

Fragmented data suggest that bisphenol AF (BPAF), a chemical widely used in a variety of products, might have potential impacts on the hypothalamus. Here, we employed male neonatal mice following maternal exposure to explore the effects of low-dose BPAF on hypothalamic development by RNA-sequencing. We found that maternal exposure to approximately 50 µg/(kg·day) BPAF from postanal day (PND) 0 to PND 15 altered the hypothalamic transcriptome, primarily involving the pathways and genes associated with extracellular matrix (ECM) and intercellular adhesion, neuroendocrine regulation, and neurological processes. Further RNA analysis confirmed the changes in the expression levels of concerned genes. Importantly, we further revealed that low-dose BPAF posed a stimulatory impact on pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus and induced the browning of inguinal white adipose tissue. All findings indicate that developmental exposure to low-dose BPAF could interfere with hypothalamic development and thereby lead to alterations in the metabolism. Interestingly, 5000 µg/(kg·day) BPAF caused slighter, non-significant or even inverse alterations than the low dose of 50 µg/(kg·day), displaying a dose-independent effect. Further observations suggest that the the dose-independent effects of BPAF might be associated with oxidative stress and inflammatory responses caused by the high dose. Overall, our study highlights a risk of low-dose BPAF to human neuroendocrine regulation and metabolism.

Toxic effects of environmental concentration Bisphenol AF exposure on the survival, growth and reproduction of adult male Oryzias curvinotus

Bisphenol AF (BPAF) is a novel environmental endocrine disruptor, and is widely detected in the aquatic environment, which is a potential threat to the health of fish. In this study, male Oryzias curvinotus were exposed to environmental concentrations (0.93 and 9.33 μg/L) of BPAF for 21 days. The effects of BPAF on survival, growth, reproduction, liver and testis histology, and gene transcriptional profiles of O. curvinotus were investigated. The results showed that the survival rate of male O. curvinotus slight decrease with increasing BPAF concentration, and there was no significant effect on body length, body weight, and K-factor. BPAF (9.33 μg/L) caused significant changes in testicular structure and reduced spermatid count in O. curvinotus. Changes in transcript levels of some antioxidant-related genes in gills and liver following BPAF exposure, imply an effect of BPAF on the immune system. After BPAF exposure, chgs and vtgs were up-regulated, validating the estrogenic effect of BPAF. In the hypothalamic - pituitary - gonadal axis (HPG) results, erα, erγ and cyp19a1b were all up-regulated in the brain, and the 0.93 μg/L BPAF group was more up-regulated than the 9.33 μg/L BPAF group. In testis, BPAF significantly up-regulated the mRNA expression level of cyp17a1 and cyp11b, while significantly down-regulated mRNA expression level of cyp11a, and cyp19a1 was significantly down-regulated only in the 0.93 μg/L BPAF group. In conclusion, environmental levels of BPAF have adverse effects on the survival and reproduction of O. curvinotus, and the potential toxic effects of environmental levels of BPAF cannot be ignored.

Structural Studies on the Binding Mode of Bisphenols to PPARγ

Bisphenol A (BPA) and bisphenol B (BPB) are widely used in the production of plastics, and their potential adverse health effects, particularly on endocrine disruption and metabolic health, have raised concern. Peroxisome proliferator-activated receptor gamma (PPARγ) plays a pivotal role in metabolic regulation and adipogenesis, making it a target of interest in understanding the development of obesity and associated health impacts. In this study, we employ X-ray crystallography and molecular dynamics (MD) simulations to study the interaction of PPARγ with BPA and BPB. Crystallographic structures reveal the binding of BPA and BPB to the ligand binding domain of PPARγ, next to C285, where binding of partial agonists as well as antagonists and inverse agonists of PPARγ signaling has been previously observed. However, no interaction of BPA and BPB with Y437 in the activation function 2 site is observed, showing that these ligands cannot stabilize the active conformation of helix 12 directly. Furthermore, free energy analyses of the MD simulations revealed that I341 has a large energetic contribution to the BPA and BPB binding modes characterized in this study.

Occurrence, source apportionment and ecological risk of bisphenol analogues in river sediments in areas with different land use patterns

Bisphenol analogues (BPs) have gained increasing attention in recent years due to their ubiquitousness and potential endocrine disrupting properties in environments. However, little information is available on their spatiotemporal distribution, source apportionment and ecological risk in river sediments, especially the case in river basins with a high population density and those typical regions with agricultural-urban gradient, where land use patterns and intensity of human activity are varying. In this study, field investigations of BPs in the sediment of the entire Qinhuai River Basin, a typical agricultural-suburban agricultural-urban gradient area, were conducted before and after the flood period. Thirty-two sites were sampled for six types of BPs, resulted in no significant difference in the concentration of ΣBPs between the two periods, with ΣBPs ranging from 3.92 to 151 ng/g and 2.16-59.0 ng/g, respectively. Bisphenol A (BPA) was the main contributor. Whereas a multivariate analysis of variance (MANOVA) suggested that the composition structure of BPs had been influenced by water periods. The land use patterns had an impact on the distribution of ΣBPs in river sediments, which was more significant in after the flood period, with ΣBPs in urban rivers was 1.85 times, 3.44 times, and 3.08 times higher than the suburban rivers, agricultural rivers, and reservoirs, respectively. Yet land use types did not significantly alter the composition structure of BPs. The correlation analysis between BPs and the physicochemical properties of sediments showed a significant positive correlation between BPA and total organic carbon (TOC). The positive matrix factorization model (PMF) suggested that BPs in sediments of the basin might be influenced by industrial coatings, textiles, electronics and biopharmaceuticals, as well as urban wastewater or solid waste generated from daily life. The ecological risk assessment posed by BPA, based on the risk quotient, indicated that the ecological risk of BPA in sediments was low for three indicator benthic organisms: crustaceans, worms, and mollusks. However, the risk of BPA in river sediments varied among different land use patterns, with the risk ranking as follows: reservoirs < agricultural rivers < suburban rivers < urban rivers.

Effects of Acute and Developmental Exposure to Bisphenol S on Chinese Medaka (Oryzias sinensis)

Bisphenol S (BPS), one of the substitutes for bisphenol A (BPA), is widely used in various commodities. The BPS concentrations in surface water have gradually increased in recent years, making it a predominant bisphenol analogue in the aquatic environment and raising concerns about its health and ecological effects on aquatic organisms. For this study, we conducted a 96 h acute toxicity test and a 15-day developmental exposure test to assess the adverse effects of BPS exposure in Chinese medaka (Oryzias sinensis), a new local aquatic animal model. The results indicate that the acute exposure of Chinese medaka embryos to BPS led to relatively low toxicity. However, developmental exposure to BPS was found to cause developmental abnormalities, such as decreased hatching rate and body length, at 15 dpf. A transcriptome analysis showed that exposure to different concentrations of bisphenol S often induced different reactions. In summary, environmental concentrations of BPS can have adverse effects on the hatching and physical development of Chinese medaka, and further attention needs to be paid to the potential toxicity of environmental BPS.

Estimating the temporal and spatial distribution and threats of bisphenol A in temperate lakes using machine learning models

Bisphenol A (BPA) is easily enriched in many human-disturbed watersheds, particularly lakes with poor water mobility, which is posing a threat to aquatic biota. While previous studies have focused on the concentration of BPA in water and its toxicity to aquatic organisms, a small amount of measured data is not enough to reveal the temporal and spatial distribution and threats of BPA, and estimate the ecological risk in watersheds. Therefore, we collected 164 measured BPA data points from Taihu Lake to develop machine learning models using random forest (RF), support vector machine (SVM) and least square regression (LSR) and created month-by-month watershed prediction maps in temperate lakes to estimate the spatiotemporal distribution and threats of BPA. Due to RF's superior robustness to noisy data, the RF model exhibits the best performance among the three algorithms. The RF model showed acceptable predictive performance on the modeling dataset (coefficients of determination and root-mean-square error for the training set were 0.927 and 17.499, respectively, and 0.607, 39.645 for the validation set, respectively). The maps indicated that areas susceptible to anthropogenic activities were more severely polluted by BPA, and rainy climate may favor the migration of BPA to aquatic ecosystems. The model was also applied to predict 42 data points of BPA collected from Dianchi Lake, and the results showed that most predicted data were within a factor of 10 of the measured data, but the prediction accuracy of the model has declined. The ecological risks in the two lakes were evaluated and attention should be paid to the regions with higher risks. Our study provided a novel idea for comprehensive monitoring of an unconventional trace pollutant with endocrine disrupting effects in aquatic ecosystems and analyzing their spatiotemporal distribution, which will contribute to the scientific assessment of the ecological risk of BPA.

Parabens, Triclosan and Bisphenol A in Surface Waters and Sediments of Baiyang Lake, China: Occurrence, Distribution, and Potential Risk Assessment

The extensive use of the parabens triclosan (TCS) and bisphenol A (BPA) has potential adverse effects on human health and aquatic organisms. However, their monitoring information in freshwater lakes is still limited. This study simultaneously summarized the concentrations, spatial distribution characteristics, and correlations of four types of parabens, TCS, and BPA in the surface water and sediment of Baiyang Lake. Finally, the potential risks of target pollutants were evaluated from two aspects: human health risks and ecological risks. The average contaminations of target compounds in surface water and sediment-BPA, TCS, and ∑4 parabens-was 33.1, 26.1, 0.7 ng/L and 24.5, 32.5, 2.5 ng/g, respectively. The total concentration of target compounds at the inlet of the upstream Fu River and Baigouyin River is significantly higher than that near Hunan and the outlet. In addition, Spearman's correlation analysis showed a significant positive correlation between compounds. The health hazards of target compounds in surface water were all within safe limits. However, the risk quotient results indicate that in some locations in surface water, TCS poses a high risk to algae and a moderate risk to invertebrates and fish, and appropriate attention should be paid to these areas.

Invisible Hand behind Female Reproductive Disorders: Bisphenols, Recent Evidence and Future Perspectives

Reproductive disorders are considered a global health problem influenced by physiological, genetic, environmental, and lifestyle factors. The increased exposure to bisphenols, a chemical used in large quantities for the production of polycarbonate plastics, has raised concerns regarding health risks in humans, particularly their endocrine-disrupting effects on female reproductive health. To provide a basis for future research on environmental interference and reproductive health, we reviewed relevant studies on the exposure patterns and levels of bisphenols in environmental matrices and humans (including susceptible populations such as pregnant women and children). In addition, we focused on in vivo, in vitro, and epidemiological studies evaluating the effects of bisphenols on the female reproductive system (the uterus, ovaries, fallopian tubes, and vagina). The results indicate that bisphenols cause structural and functional damage to the female reproductive system by interfering with hormones; activating receptors; inducing oxidative stress, DNA damage, and carcinogenesis; and triggering epigenetic changes, with the damaging effects being intergenerational. Epidemiological studies support the association between bisphenols and diseases such as cancer of the female reproductive system, reproductive dysfunction, and miscarriage, which may negatively affect the establishment and maintenance of pregnancy. Altogether, this review provides a reference for assessing the adverse effects of bisphenols on female reproductive health.

Neurodevelopmental toxicity of bisphenol AF in zebrafish larvae and the protective effects of curcumin

Bisphenol AF (BPAF) is one of the most commonly used alternatives of bisphenol A in the plastics industry. The effects of BPAF on nervous development are unclear. Curcumin (CUR) has been determined to be an anti-inflammatory and antioxidant agent. In this study, the effects of BPAF on neurotoxicity of zebrafish embryos/larvae and whether CUR could reverse effects induced by BPAF were investigated. The results showed that BPAF treatment induced deficits in locomotor behavior, altered the larval brain development, caused aberrant expression of neurogenesis related genes (elavl3, zn5, α-tubulin, syn2a, and gap43), decreased acetylcholinesterase (AChE) activity, and induced oxidative stress, cell apoptosis, and neuroinflammation in zebrafish larvae. CUR addition could block the adverse effects of BPAF on nervous development by attenuated oxidative stress and cell apoptosis induced by BPAF in zebrafish, enhanced the activity of AChE, and increased the expression of genes involved in the pro-inflammatory cytokines (IL-6, IL-1β, TNF-α, and IL-8). The results of this study indicate that BPAF could induce aberrant development on nervous system. However, CUR exerts neuroprotective effects on BPAF-induced neurotoxicity in zebrafish larvae.

Spatial nanopores promote laccase degradation of bisphenol A and its analogs

Bisphenol A (BPA) and its analogs are endocrine-disrupting chemicals that are frequently detected in environmental and human samples. However, the effective removal of BPA and its analogs has not yet been extensively studied. Herein, we introduce a novel enzyme reactor for the degradation of BPA and its analogs in water. The influence of pore size on the degradation efficiency of immobilized laccase in the spatial nanopores of hydrogel was investigated using BPA as a representative compound. This showed that nanopores enhance the activity of immobilized laccases in a pore size-dependent manner and increase their stability. Compared with the same amount of free laccase, the 50 mg/L BPA degradation performance of laccase immobilized in 76 nm nanopores increased to 300 %. Taking advantage of magnetic separation, this immobilized laccase can be reused, and its degradation capacity was maintained at over 73.7 % after ten reactions. Moreover, the degradation of seven BPA analogs was 1.03-5.88 times higher using laccase immobilized in nanopores compared with free laccase. Also, the biocatalyst could efficiently degrade BPA analogs in real water matrix. This study opens up a new avenue for the removal of BPA and its analogs by immobilizing laccase in nanopores, overcoming the key limitations introduced by the short enzyme life span and non-reusability.

Transcriptome Analysis of the Developmental Effects of Bisphenol F Exposure in Chinese Medaka (Oryzias sinensis)

Bisphenol F (BPF) has been used in the syntheses of polymers, which are widely used in coatings, varnishes, adhesives, and other plastics. During the past decades, BPF contamination in the aquatic environment has dramatically increased due to its release from manmade products. Concerns have driven much attention to whether it may adversely impact aquatic lives or human beings. The present study performed an acute toxic exposure experiment and a 15 d developmental exposure of BPF at environmental concentrations (20, 200, and 2000 ng/L) using Chinese medaka (Oryzias sinensis). In the acute toxic exposure, the LC₅₀ of BPF to Chinese medaka is 87.90 mg/L at 96 h. Developmental exposure induced a significant increase in the frequency of larvae with abnormalities in the 2000 ng/L BPF group compared to the control group. Transcriptomic analysis of the whole larvae revealed 565 up-regulated and 493 down-regulated genes in the 2000 ng/L BPF exposure group. Analysis of gene ontology and KEGG pathways enrichments indicated endocrine disorders to be associated with BPF-induced developmental toxicity. The present results suggest that BPF is developmentally toxic at 2000 ng/L concentration in Chinese medaka and causes endocrine-related aberrations in the transcriptional network of genes.

The effects of bisphenols on the cardiovascular system ex vivo and in vivo

The human population is regularly exposed to bisphenols. The first compound of this class, bisphenol A, is burdened by numerous reports of its potential toxicity and has been hence replaced by its analogues, so-called next generation bisphenols. Their widespread use has made them pervasive throughout the environment. These endocrine disrupting chemicals can affect the cardiovascular system, and hence the aim of this study was to test 14 bisphenols (A, AF, AP, B, BP, C, E, F, G, M, P, PH, S and Z), and compare their effects in vitro (human and rat cell lines), ex vivo (isolated rat aorta) and in vivo (Wistar Han rats, acutely or chronically exposed to low environmental and high toxic doses). The majority of the tested bisphenols relaxed rat aorta, but their potency varied markedly. The most potent compound, bisphenol AF, had an EC₅₀ of 57 μM. The mechanism of action was likely based on the inhibition of calcium influx via L-type calcium channels. The cytotoxicity of bisphenols towards 4 human and rat cell lines (H9c2, A-10, MCF7/S0.5 and MCF7/182R-6) showed variable potencies ranging from units of micromolar to millimolar concentrations. Based on these data, an effect on arterial blood pressure and possible cardiotoxicity was expected. Contrarily, the in vivo acute effects of three doses (0.005, 0.05 and 2.5 mg/kg) of bisphenol AF and 3 other analogues (A, S and F) on the cardiovascular system were rather biologically negligible. The most potent bisphenol, AF, was also administered chronically at a dose of 2.5 mg/kg for 4 weeks to rats, but had no impact on arterial blood pressure. Our results showed that bisphenols can relax vascular smooth muscles, but the effective concentrations are too high to produce clear cardiovascular effects in relation to common biological exposure as was confirmed with the most potent bisphenol AF.

Bisphenol A and its substitutes in the aquatic environment: Occurrence and toxicity assessment

Bisphenol A is classified as a high production volume chemical commonly used in the manufacture of polycarbonate plastics, epoxy resins and thermal paper. The endocrine disrupting properties of this xenobiotic have led to the restriction and prohibition of its use in many consumer products. To date, many chemical compounds with a chemical structure similar to bisphenol A have been used in consumer products as its replacement. The ubiquitous occurrence of bisphenol A and its substitutes in the environment and their endocrine activity as well as adverse effects on aquatic organisms is a global concern, especially because many available literature reports show that many substitutes (e.g. bisphenol AF, bisphenol AP, bisphenol B, bisphenol C, bisphenol F, bisphenol G, bisphenol FL, tetrabromobisphenol A) exert adverse effects on aquatic organisms, similar to, or even stronger than bisphenol A. Therefore, the objective of this paper is to provide a comprehensive overview of the production, sources, occurrence and associated toxicity, as well as the endocrine activity of bisphenol A and its substitutes on aquatic species. The environmental levels and ecotoxicological data presented in this review allowed for a preliminary assessment and prediction of the risk of bisphenol A and its substitutes for aquatic organisms. Furthermore, the data collected in this paper highlight that several compounds applied in bisphenol A-free products are not safe alternatives and regulations regarding their use should be introduced.

The toxic effect of bisphenol AF and nanoplastic coexposure in parental and offspring generation zebrafish

Microplastics (MPs) and bisphenol AF (BPAF) are two environmental pollutants that usually coexist in the natural environment. Studies of MPs or BPAF have gradually increased in recent years, but few studies have focused on the combination toxic effects. In this study, the subchronic model of adult zebrafish was exposed to 1 mg/L nanolevel microplastics and 200 μg/L BPAF for 45 days; the parental zebrafish were spawning every 3 days during exposure, and the effects of continuous poisoning were examined on the offspring after 1-9 spawns. The results showed that single BPAF exposure or BPAF and nanoplastic coexposure can both decrease the number of eggs laid and the locomotor behavior of parental zebrafish and impact the hatching rate, mortality, body length and locomotor behavior of offspring zebrafish, especially in 7-9 spawn. BPAF were accumulated in parental zebrafish intestinal in 334.62 ng/g in BPAF group and 594.52 ng/g in nm+BPAF group, and accumulated in whole offspring zebrafish for 281.6 ng/g in BPAF group and 321.46 ng/g in nm+BPAF group. Neurodevelopmental, inflammation, apoptosis and oxidative stress-related genes were also significantly increased after 7-9 spawn. In addition, the exacerbated accumulation in the BPAF+nm group in parental and offspring zebrafish may be the reason for the accelerated toxic effect in the present research. In this study, we investigated the combined effects of nanoplastics and BPAF on parental and offspring zebrafish in the aquatic environment to identify the accumulative toxic effects and provide new experimental support for assessing the effects of coexposure on aquatic organisms.

Bisphenol analogues in water and sediment from the Beibu Gulf, South China Sea: Occurrence, partitioning and risk assessment

Bisphenol analogues (BPs) have gained increasing attention in recent years due to their ubiquitousness in the environment, potential endocrine disrupting properties and ecological impacts. However, very little information is available on the occurrence, partitioning and ecological risks of BPs in marine environments. In the present study, six BPs were investigated in surface water and sediment samples from the Beibu Gulf, South China Sea. Results showed that bisphenol A (BPA) was the predominant BP in both water and sediment samples with levels ranging from 5.26 to 12.04 ng/L in water and 0.56 to 5.22 ng/g dw in sediment samples, followed by bisphenol AF (BPAF: 0.44-0.60 ng/L in water and 0.08-0.66 ng/g dw in sediment samples, respectively) and bisphenol S (BPS: 0.07-0.63 ng/L in water and not detected (ND) to 0.19 ng/g dw in sediment samples, respectively). There is no significant spatial difference of BPs levels between riverine sediment samples and coastal sediment samples. Compared with other studies, the concentrations of BPs from the Beibu Gulf were relatively low. The mean log-transformed sediment-seawater partitioning coefficients (log K_oc) ranged from 4.4 (DHBP) to 5.2 (BPAF) and the log K_oc values for all the target BPs were generally higher than those reported in freshwater environments. The present study firstly reported the field-based log K_oc values for BPB (mean: 4.5) and DHBP (mean: 4.4). The estimated risk quotient (RQ) and 17β-estradiol (E2) equivalent quotient (EEQ) values indicated that the ecological and human health impacts were negligible associated with target BPs. The present study provided reliable and detailed data for completely evaluating contamination level and environmental behaviors of BPs in the Beibu Gulf.

The occurrence, fate, toxicity, and biodegradation of phthalate esters: An overview

Phthalate esters (PAEs) are a class of emerging xenobiotic compounds that are extensively used as plasticizers. In recent times, there has been an increasing concern over the risk of this pervasive pollution exposure causing endocrine disruption and carcinogenicity in humans and animals. The widespread use of PAEs in home and industrial applications has resulted in their discharge in aquatic bodies via leaching, volatilization, and precipitation. In this overview, the current state of PAE pollution, its potential origins, its fate, as well as its effects on the aquatic environment are discussed. A state-of-the-art review of several studies in the literature that focus on the biological degradation of PAEs is included in this study. The paper aims to provide a comprehensive view of current research on PAEs in the environment, highlighting its fate and alleviated risks on the aquatic biotas, their challenges, future prospects, and the need for good management and policies for its remediation. PRACTITIONER POINTS: Occurrence of phthalate esters was summarized in various environmental matrices along with its serious ecotoxicological implications on biota. Wastewater is the prime source of PAEs contamination. Lack of species-specific effects on biota due to dose, exposure route, and susceptibility. The predominant route to mineralization in PAEs is biodegradation. A critical analysis of worldwide PAE production and consumption identifies the necessity for global PAE production, consumption, and release policies.

Dualistic effects of bisphenol A on growth, photosynthetic and oxidative stress of duckweed (Lemna minor)

In this study, we exposed duckweed (Lemna minor), a floating freshwater plant, to BPA at different concentrations (0, 1, 5, 20, and 50 mg/L) for 7 days so as to investigate the effects of BPA on its growth, photosynthesis, antioxidant system, and osmotic substances. It was found that BPA had the acute toxic effects of "low promotion and high inhibition" on growth and photosynthesis. Specifically, BPA at a low concentration (5 mg/L) significantly promoted the plant growth and improved the concentration of photosynthetic pigments (chlorophyll a, b, and total Chl ) of L. minor. However, BPA at a high concentration (50 mg/L) significantly inhibited the plant growth, the Chl content, and the maximal photochemical efficiency (F_v/F_m). Furthermore, BPA with high concentration (50 mg/L) induced ROS accumulation and increased the activities of antioxidant enzymes (SOD, CAT, POD, APX, and GR) and the contents of antioxidant substances (GSH, proline, and T-AOC), which indicated that L. minor might tolerate BPA toxicity by activating an antioxidant defense system. The correlation analysis revealed that the fresh weight of L. minor was significantly and positively correlated with photosynthesis and the contents of soluble protein and sugar, while it was negatively correlated with the content of H₂O₂. Totally, these results showed that BPA at different concentrations had dualistic effects on the growth of L. minor, which was attributed to the alterations of photosynthesis, oxidative stress, and osmotic regulation systems and provided a novel insight for studying the effects of BPA on aquatic plant physiology.

Effects of bisphenol AF on growth, behavior, histology and gene expression in marine medaka (Oryzias melastigma)

Bisphenol AF (BPAF) is one of the substitutes for bisphenol A (BPA), which has endocrine-disrupting, reproductive and neurological toxicity. BPAF has frequently been detected in the aquatic environment, which has been a long-term threat to the health of aquatic organisms. In this study, female marine medaka (Oryzias melastigma) were exposed to 6.7 μg/L, 73.4 μg/L, and 367.0 μg/L BPAF for 120 d. The effects of BPAF on behavior, growth, liver and ovarian histology, gene transcriptional profiles, and reproduction of marine medaka were determined. The results showed that with the increase of BPAF concentration, the swimming speed of female marine medaka showed an increasing trend and then decreasing trend. BPAF (367.0 μg/L) significantly increased body weight and condition factors in females. BPAF (73.4 μg/L and 367.0 μg/L) significantly delayed oocyte maturation. Exposure to 367.0 μg/L BPAF showed an increasing trend in the transcript levels of lipid synthesis and transport-related genes such as fatty acid synthase (fasn), sterol regulatory element binding protein (srebf), diacylglycerol acyltransferase (dgat), solute carrier family 27 member 4 (slc27a4), fatty acid-binding protein (fabp), and peroxisome proliferator-activated receptor gamma (pparγ) in the liver. In addition, 6.7 μg/L BPAF significantly down-regulated the expression levels of antioxidant-related genes [superoxide dismutase (sod), glutathione peroxidase (gpx), and catalase (cat)], and complement system-related genes [complement component 5 (c5), complement component 7a (c7a), mannan-binding lectin serine peptidase 1 (masp1), and tumor necrosis factor (tnf)] were significantly up-regulated in the 73.4 and 367.0 μg/L groups, which implies the effect of BPAF on the immune system in the liver. In the hypothalamic-pituitary-ovarian axis (HPG) results, the transcription levels of estrogen receptor α (erα), estrogen receptor β (erβ), androgen receptor (arα), gonadotropin-releasing hormone 2 (gnrh2), cytochrome P450 19b (cyp19b), aromatase (cyp19a), and luteinizing hormone receptor (lhr) in the brain and ovary, and vitellogenin (vtg) and choriogenin (chg) in the liver of 367.0 μg/L BPAF group showed a downward trend. In addition, exposure to 367.0 μg/L BPAF for 120 d inhibited the spawning behavior of marine medaka. Our results showed that long-term BPAF treatment influenced growth (body weight and condition factors), lipid metabolism, and ovarian maturation, and significantly altered the immune response and the transcriptional expression levels of HPG axis-related genes.

A holistic assessment of the sources, prevalence, and distribution of bisphenol A and analogues in water, sediments, biota and plastic litter of the Ebro Delta (Spain)

Bisphenol A (BPA) is one of the main ubiquitous compounds released from plastics in the environment. This compound, considered an endocrine disruptor, poses a risk to aquatic wildlife and human population, being included in multiple environmental monitoring programmes. Following the regulations restricting BPA use in the last years, BPA-like chemicals have been produced and used as BPA substitutes. However, they are not commonly included in monitoring programs yet and their presence is thus misrepresented, despite showing similar endocrine disrupting potential. In this work, an analytical method for analysing bisphenol A and five of its analogues (Bisphenol S, B, F, AF and Tetrabromobisphenol A) is described, validated for water (riverine, sea and wastewater), sediment, and biota (fish and biofilm) and applied to monitor their presence in the Ebro River Delta (NE Spain). In addition, plastic litter was also collected to evaluate their role as potential source of bisphenols. All compounds except BPF were detected in the analysed samples. Wastewater treatment plants (WWTPs) were discarded as major sources of BPs into the natural aquatic environment, as no BPs were detected in treated effluents. Indeed, the high levels of BPs in the natural environment could be related with direct discharge of raw wastewater from small rural population nucleus. The analysis of riverine plastic leachates yielded 4 out of the 6 BPs analysed, strengthening the hypothesis that plastic debris are also a source of BPs in the natural environment. Whereas Bisphenol S and BPA were detected in water and, to a limited extent, in biota, less polar analogues (mainly BPAF and TBBPA) were not found in any of the water samples. Instead, these hydrophobic BPs were found in fish tissues and biofilm, pointing out plastics and microplastics as their possible vectors. Finally, biofilm demonstrated its potential as sentinel of chemical contamination in freshwater environment.

Bisphenol AF Promoted the Growth of Uterus and Activated Estrogen Signaling Related Targets in Various Tissues of Nude Mice with SK-BR-3 Xenograft Tumor

Environmental estrogens can promote the growth, migration, and invasion of breast cancer. However, few studies evaluate adverse health impacts of environmental estrogens on other organs of breast cancer patients. Therefore, the present study investigated the effects of environmental estrogen bisphenol AF (BPAF) on the main organs of female Balb/cA nude mice with SK-BR-3 xenograft tumor by detecting the organ development and gene expression of targets associated with G protein-coupled estrogen receptor 1 (GPER1)-mediated phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) and mitogen-activated protein kinase (MAPK) signaling pathways in hypothalamus, ovary, uterus, liver, and kidney. The results showed that BPAF at 20 mg/kg bw/day markedly increased the uterine weight and the uterine coefficient of nude mice compared to SK-BR-3 bearing tumor control, indicating that BPAF promoted the growth of uterus due to its estrogenic activity. Additionally, BPAF significantly up-regulated the mRNA relative expression of most targets related to nuclear estrogen receptor alpha (ERα) and GPER1-mediated signaling pathways in the hypothalamus, followed by the ovary and uterus, and the least in the liver and kidney, indicating that BPAF activated different estrogen activity related targets in different tissues. In addition, BPAF markedly up-regulated the mRNA expression of GPER1 in all tested tissues, and the molecular docking showed that BPAF could dock into GPER1. Because gene change is an early event of toxicity response, these findings suggested that BPAF might aggravate the condition of breast cancer patients through exerting its estrogenic activity via the GPER1 pathway in various organs.

Stable magnetic CoZn/N-doped polyhedron with self-generating carbon nanotubes for highly efficient removal of bisphenols from complex wastewaters

Bisphenols have extensively been found in various environmental matrices and caused public concerns due to their endocrine-disrupting potential. Herein, we developed a ZIF-67@ZIF-8-derived CoZn/nitrogen-doped carbon (CoZn/NC) as a robust adsorbent for bisphenols in wastewaters. The self-generating carbon nanotubes and the open metal sites provided sufficient adsorption sites. The Co component endowed the derivative with strong magnetism facilitating its separation from water. CoZn/NC exhibited exceeding water stability in pH 3 - 12 solution and withstood water up to 15 days. The great applicability of CoZn/NC was validated with 16 real wastewaters from different sources (recoveries exceeding 97.9%). Fast adsorption kinetics were observed with removal efficiencies above 96.5% within 1 min. The adsorption isotherms were well fitted with the Langmuir model, with adsorption capacities of 222, 200, 193, and 321 mg g^-1 for bisphenol A, bisphenol F, bisphenol S, and bisphenol AF, respectively. Variations in external conditions, including pH 3 - 9, humic acid (50 mg L^-1), and NaCl (0.1 mol L^-1), had negligible impacts on the adsorption process. The characterizations and density functional theory computation demonstrated that electrostatic, hydrophobic, π - π, and cation- π interactions are the driving forces in this system. The as-prepared CoZn/NC exhibits great promise in real wastewater treatment.

Effects of low-dose bisphenol AF on mammal testis development via complex mechanisms: alterations are detectable in both infancy and adulthood

Despite growing concern about adverse effects of bisphenol AF (BPAF) due to its endocrine disrupting properties, there is a lack of toxicity data from low-dose studies and direct evidence linking its adverse effects to endocrine disrupting properties. Here, we investigated the effects of gestational and postnatal exposure to BPAF through drinking water (0.15-15 μg/mL, equivalent to the daily intake of ~ 50 and 5 mg/kg/day) on testis development in mice. We found that like mestranol, 5 mg/kg/day BPAF resulted in remarkable decreases in multiple male reproductive parameters in adulthood, such as the sperm number and serum testosterone level. Notably, 50 μg/kg/day BPAF also caused significant decreases in anogenital distance (AGD), the luteinizing hormone level and spermatocyte number, along with declining trends in sperm number and the serum levels of testosterone and follicle-stimulating hormone. In line with the adverse outcomes observed in adulthood, on postnatal day (PND) 9, we also observed BPAF-caused dose-dependent alterations, including reduced AGD, seminiferous tubule area and numbers of total germ cells, spermatocytes and Leydig cells, coupled with down-regulated expression of male-biased genes in testes. Even when exposure to 5 mg/kg/day BPAF as well as MES was initiated from PND 0, similar alterations in male reproductive parameters were also found on PND 9, along with a decrease in the GnRH content in the hypothalamus; moreover, testicular alterations and the reduction in AGD were partly antagonized by the estrogen receptor (ER) antagonist ICI 182,780, but the reduction of GnRH production was not done, showing that the effects of BPAF on testis development may be partially mediated by ER signaling. In conclusion, all the findings demonstrate that low-dose BPAF can partly disrupt mammal testis development and cause adverse testicular outcomes in adulthood, indicating a potential reproductive risk to mammals including humans. Importantly, our finding that developmental alterations elicited by BPAF have been detectable on PND 9 provides important motivation for the development of effective methods for early detection of adverse effects of estrogenic chemicals on testis development.

Multi-residue determination of bisphenol analogues in organism tissues by ultra-high performance liquid chromatography-tandem mass spectrometry

A reliable and sensitive analyzing method was developed and validated for determination of 13 novel bisphenol analogues (BPs) along with bisphenol A (BPA) in organism tissues. The complex organism tissues were treated by ultrasonic-assisted extraction using acetonitrile/formic acid (99:1, v/v), followed by successive purification using enhanced matrix removal-lipid sorbents and primary secondary amine sorbents. The BPs were finally determined by ultra-high performance liquid chromatography-tandem mass spectrometry after derivatization using pyridine-3-sulfonyl chloride. Satisfactory recoveries of 75 - 118% were obtained for the BPs, with good repeatability (RSD < 20%). Matrix interferences were efficiently diminished. The method quantification limits (MQLs) reached 0.003 - 0.1 ng g^-1 dry weight (dw). The validated method was successfully applied to a preliminary investigation of the BPs in wild marine organisms collected from the nearshore waters along the coast of Guangdong, China. Besides BPA, novel BPs such as bisphenol F, bisphenol AF, and tetrabromobisphenol A were also detected at < MDL - 15.5 ng g^-1 dw. This work laid a strong basis for further in-depth research on bioaccumulation of the novel BPs in the environment.

Bisphenol A in the environment and recent advances in biodegradation by fungi

Bisphenol A (BPA) is a compound used in the manufacture of a wide variety of everyday materials that, when released into the environment, causes multiple detrimental effects on humans and other organisms. The reason for this review is to provide an overview of the presence, distribution, and concentration of BPA in water, soil, sediment, and air, as well as the process of release and migration, biomagnification, and exposure mechanisms that cause various toxic effects in humans. Therefore, it is important to seek efficient and economic strategies that allow its removal from the environment and prevent it from reaching humans through food chains. Likewise, the main removal techniques are analyzed, focusing on biological treatments, particularly the most recent advances in the degradation of BPA in different environmental matrices through the use of ligninolytic fungi, non-ligninolytic fungi and yeasts, as well as the possible routes of metabolic processes that allow their biotransformation or biodegradation due to their efficient extracellular enzyme systems. This review supports the importance of the application of new biotechnological tools for the degradation of BPA.

Testicular toxicity of bisphenol compounds: Homeostasis disruption of cholesterol/testosterone via PPARα activation

The widespread application of bisphenols (BPs) has made them ubiquitous in the environment. Although the side effects of bisphenol A (BPA) substitutes have received increasing attention, studies on their reproductive toxicity remain lacking. In this research, the effects of BPA and its substitutes, including bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF), on the male reproductive system were evaluated. Results proved that these BPs disturbed germ cell proliferation, induced germ cell apoptosis, and perturbed sperm physiologies and spermatogenesis, which resulted from the disruption of testosterone (T) biosynthesis in Leydig cells (LCs). Importantly, in vitro and in vivo studies indicated that the exhausted cholesterol in LCs accounted for the reduced T production. Furthermore, the knockdown of peroxisome proliferator-activated receptor alpha (PPARα) remarkably ameliorated the downregulation of cholesterogenesis-related genes (i.e., Hmgcs1, Hmgcr, and Srebf2), indicating that PPARα played a critical role in BPs-induced testicular dysfunction. Overall, our studies indicated that BPS, BPF, and BPAF could induce testicular toxic effects similar to that of BPA, which were associated with the PPARα pathway.

Microfiltration Membranes for the Removal of Bisphenol A from Aqueous Solution: Adsorption Behavior and Mechanism

This study mainly investigated the adsorption behavior and mechanism of microfiltration membranes (MFMs) with different physiochemical properties (polyamide (PA), polyvinylidene fluoride (PVDF), nitrocellulose (NC), and polytetrafluoroethylene (PTFE)) for bisphenol A (BPA). According to the adsorption isotherm and kinetic, the maximum adsorption capacity of these MFMs was PA (161.29 mg/g) > PVDF (80.00 mg/g) > NC (18.02 mg/g) > PTFE (1.56 mg/g), and the adsorption rate was PVDF (K1 = 2.373 h−1) > PA (K1 = 1.739 h−1) > NC (K1 = 1.086 h−1). The site energy distribution analysis showed that PA MFMs had the greatest adsorption sites, followed by PVDF and NC MFMs. The study of the adsorption mechanism suggested that the hydrophilic microdomain and hydrophobic microdomain had a micro-separation for PA and PVDF, which resulted in a higher adsorption capacity of PA and PVDF MFMs. The hydrophilic microdomain providing hydrogen bonding sites and the hydrophobic microdomain providing hydrophobic interaction, play a synergetic role in improving the BPA adsorption. Due to the hydrogen bonding force being greater than the hydrophobic force, more hydrogen bonding sites on the hydrophobic surface resulted in a higher adsorption capacity, but the hydrophobic interaction contributed to improving the adsorption rate. Therefore, the distribution of the hydrophilic microdomain and hydrophobic microdomain on MFMs can influence the adsorption capacity and the adsorption rate for BPA or its analogues. These consequences provide a novel insight for better understanding the adsorption behavior and mechanism on MFMs.

Generality and diversity on the kinetics, toxicity and DFT studies of sulfate radical-induced transformation of BPA and its analogues

The international campaign to ban bisphenol A (BPA) has resulted in increasing application of BPA substitutes. However, investigations have mainly been confined to the removal of single contaminant from the water, resulting in an inefficient burden. Furthermore, systematic study and synthetical discussion of bisphenol analogues (BPs) kinetics and transformation pathways were largely underemphasized. Chemical oxidation of BPA and four typical alternatives (i.e., bisphenol AF, bisphenol E, bisphenol F and bisphenol S) in a UV-activated persulfate system was examined in this study. The effects of persulfate (PS) dosage, pH and water matrix constituents (i.e., bicarbonate, chloride and natural organic matter) were comprehensively examined using a combination of laboratory experiments and mathematical modeling. According to our findings, the removal characteristics of different BPs employing SO₄•^--induced removal technology, including degradation mechanisms and influencing trends by water matrix, revealed similarly. The second order-rate constants of SO₄•^- reacting with BPs served as the main variables mediating the variation in degradation kinetics. Frontier molecular orbital theory and density functional theory suggested BPs molecules possessed the same susceptible positions to free radicals. In the UV-activated PS process, transformation pathways included hydroxylation, electron-transfer, substitution, and rearrangement triggered by ortho-cleavage, with certain intermediates exhibiting higher toxicity than the parent chemicals. The findings of this study provided valuable information to estimate potential environmental risks of using BPA alternatives.

Bisphenol chemicals disturb intestinal homeostasis via Notch/Wnt signaling and induce mucosal barrier dysregulation and inflammation

Emerging evidence has shown that bisphenol A (BPA) can exert adverse effects on intestinal barrier in rodents, but little is known about its underlying mechanisms. We previously found BPA and its substitute bisphenol F (BPF) disrupted Notch signaling and altered intestinal histological structures in Xenopus laevis tadpoles. The present study aimed to determine whether BPA and BPF could affect intestinal homeostasis via Notch/Wnt signaling and induce intestinal barrier dysregulation in adult mammals, given the fundamental roles of the two conserved signaling pathways in intestinal homeostasis and regulation of intestinal barrier. We found that following 7-day administration with BPA or BPF through drinking water at the reference dose of 50 μg/kg/d and no observed adverse effect level of 5 mg/kg/d (NOAEL) of BPA, adult male mice displayed no alterations at histological and cellular levels in colons, but high dose of both BPA and BPF downregulated the expression of Notch- and Wnt-related genes as well as key genes responsible for intestinal homeostasis. When administration was extended to 14 days, all treatments significantly suppressed the expression of all tested Notch- and Wnt-related genes; correspondingly, administrated colons exhibited downregulated expression of key genes responsible for intestinal homeostasis and reduced cell proliferation in crypts. Importantly, all treatments suppressed secretory cell differentiation, reduced mucin protein levels and downregulated expression of tight junction markers, implicating mucosal barrier dysregulation. Furthermore, inflammatory cell infiltration and upregulated expression of inflammatory cytokine genes in colons, coupled with increased serum inflammatory cytokine levels, were observed in all treatments. All results show that both BPA and BPF at the reference dose disrupted Notch/Wnt signaling and intestinal homeostasis, thereby leading to mucosal barrier dysregulation and intestinal inflammation in mice. This is the first study revealing the adverse influences of BPF on mammal intestines and underlying mechanisms for bisphenol-caused intestinal injury.

Key role of suspended particulate matter in assessing fate and risk of endocrine disrupting compounds in a complex river-lake system

Endocrine-disrupting compounds (EDCs) enter lakes mainly through river inflow. However, the occurrence, transport and fate of EDCs in the overlying water, suspended particulate matter (SPM) and sediment of inflowing rivers remain unclear. This study investigated the load of seven EDCs in a complex river-lake system of the Taihu Lake Basin during different seasons, with the aims of revealing the transport routes of EDCs and identifying the contributions from different sources. The results indicated that the levels of the seven EDCs in the wet season with high temperature and dilution effects were generally lower than those in the other seasons. EDC enrichment in the sediment was largely affected by the transport and fate of SPM. Moreover, the estrogenic activity and risks of EDCs were the highest in SPM. The mass loadings of particulate EDCs carried by SPM were 2.6 times that of overlying water. SPM plays a vital role in the transport and fate of EDCs in complex river-lake systems and thereby deserves more attention. Nonpoint sources, particularly animal husbandry activities and untreated domestic sewage, were the main sources of EDCs, amounting to 61.5% of the total load.

Intergenerational toxic effects of parental exposure to bisphenol AF on offspring and epigenetic modulations in zebrafish

Bisphenol AF (BPAF), an endocrine-disrupting chemical, has been detected in various environmental media because of its wide industrial applications. Meanwhile, substances that are known to be toxic to the reproductive system have been observed to interfere with the development of the offspring following parental exposure. This study was aimed at determining the gender-dependent intergenerational effects of BPAF on offspring development following either paternal or maternal exposure of adult zebrafish to an environmental concentration of BPAF. Four-month-old zebrafish (F0) were exposed to 10 μg/L of BPAF for 28 days, the developmental endpoints of F1 embryos were then tested without further treatment with BPAF. The results show that paternal BPAF exposure decreased the hatching rate, increased mortality, and shortened the body lengths of F1 larval offspring. In addition, it changed DNA and m⁶A RNA methylation gene expression levels in F0 testes and F1 larvae. Although maternal exposure increased mortality and enhanced antioxidant enzyme activities in F1 larvae, only DNA methylation gene expression was altered in F0 ovaries and F1 larvae. In addition, a short term BPAF exposure of zebrafish embryos from 4 h post-fertilization (hpf) until 120 hpf similarly impaired the early development of the larvae but only at a level relatively higher than 10 μg/L; and DNA and RNA methylation gene expression was regulated to some extent in BPAF exposure groups. Overall, our results indicate the gender-specific effects of BPAF on offspring development and epigenetic modulations, suggesting a relatively high susceptibility within the exposure window during gametogenesis and early embryonic developmental stages to environmental chemicals.

Influence of aryl hydrocarbon receptor and sulfotransferase 1A1 on bisphenol AF-induced clastogenesis in human hepatoma cells

Bisphenol compounds (BPs) are ubiquitously existing pollutants. Recent evidence shows that they may be activated by human CYP1A1 for clastogenic effects; however, factors that influence/mediate CYP1A1-activated 4,4'-(hexafluoroisopropylidene)diphenol (BPAF) toxicity, particularly the aryl hydrocarbon receptor (AhR), sulfotransferase (SULT) 1A1 [known to conjugate 2,2-bis(4-hydroxyphenol)-propane (BPA)] and reactive oxygen species (ROS), remain unclear. In this study, a human hepatoma (HepG2) cell line was genetically engineered for the expression of human CYP1A1 and SULT1A1, producing HepG2-hCYP1A1 and HepG2-hSULT1A1, respectively. They were used in the micronucleus test and γ-H2AX analysis (Western blot) (indicating double-strand DNA breaks) with BPAF; the role of AhR in mediating BPAF toxicity was investigated by coexposure of AhR modulators in HepG2 and its derivative C3A (with no genetic modifications but enhanced CYP expression). The results indicated induction of micronuclei by BPAF (≥ 2.5 µM, for 2-cell cycle) in HepG2-hCYP1A1 and C3A, while inactive in HepG2 and HepG2-hSULT1A1; however, BPAF induced micronuclei in HepG2 pretreated with 3,3',4,4',5-pentachlorobiphenyl (PCB126, AhR activator), and BAY-218 (AhR inhibitor) blocked the effect of BPAF in C3A. In HepG2-hCYP1A1 BPAF selectively induced centromere-free micronuclei (immunofluorescent assay) and double-strand DNA breaks. In HepG2 cells receiving conditional medium from BPAF-HepG2-hCYP1A1 incubation micronuclei were formed, while negative in HepG2-hSULT1A1. Finally, the intracellular levels of ROS, superoxide dismutase and reduced glutathione in C3A and HepG2-hCYP1A1 exposed to BPAF were all moderately increased, while unchanged in HepG2 cells. In conclusion, like other BPs BPAF is activated by human CYP1A1 for potent clastogenicity, and this effect is enhanced by AhR while alleviated by SULT1A1.

Single and combined toxicity effects of nanoplastics and bisphenol F on submerged the macrophyte Hydrilla verticillata

Nano- and microplastics pose severe risks to the ecological environment. Nanoplastics (NPs) not only directly affect aquatic organisms, but also adsorb to other pollutants, resulting in compound pollution. Bisphenol F (BPF), an endocrine-disrupting chemical, is increasingly replacing bisphenol A (BPA) and is therefore widely distributed in the environment. In this study, the toxic effects of polystyrene nanoplastics (PS-NPs) and BPF and their combined exposure on the submerged macrophytes Hydrilla verticillata (H. verticillata) and leaf biofilms, were investigated. Results showed that 10 mg/L PS-NPs and combined exposure to 10 mg/L PS-NPs and 10 mg/L BPF significantly decreased the relative growth rate and chlorophyll content of H. verticillata, whereas BPF exposure alone had no impact on the growth and the contents of photosynthetic pigments in H. verticillata. Individual and combined exposure to PS-NPs and BPF can trigger antioxidant responses such as increased activities of superoxide dismutase, peroxidase, and malondialdehyde, as well as higher levels of glutathione S-transferase and glutathione and decreased catalase activity. The results of the scanning electron microscopy (SEM) showed that the nanoplastics particles were adsorbed on the surface of plant leaves, explaining their toxic effects, whereas BPF increases the sorption of PS-NPs on the surface of H. verticillata, potentially leading to PS-NPs enrichment in the food chain. The diversity and richness of the microbial community were altered by exposure to PS-NPs and BPF individually and in combination. The current study is the first to assess the effects of PS-NPs and BPF exposure on the growth, physiological characteristics, and leaf biofilm properties of submerged macrophytes.

Pollution Characteristics and Risk Prediction of Endocrine Disruptors in Lakes of Wuhan

As a new and ubiquitous trace organic pollutant, endocrine-disrupting compounds (EDCs) can cause endocrine-disrupting effects on organisms even at low levels. However, little information is available on the resource and assessment of EDC risks in the water environment. The study area was selected based on the paucity of information on the pollution status of inland lakes. Wuhan has numerous and diverse types of lakes which receive micropollutants from different pathways. In this study, the spatial distribution, occurrence, quantity and ecological risks of EDCs in 12 lakes were investigated. Five EDCs, including 17-alpha-ethinylestradiol (17α-EE₂), estrone (E₁), β-estradiol (β-E₂), estriol (E₃) and bisphenol A (BPA) were detected in surface waters. The distribution of EDC content in the lakes was ordered as follows: exurban zone < suburban area < urban areas. The pollution sources in remote lakes mainly included agricultural and aquaculture wastewater, while those in suburban and urban areas included domestic or industrial wastewater. Areas with higher EDC content were frequently related to agricultural activities, aquaculture water or dense populations. Water quality parameters, including dissolved oxygen, pH and water temperature, were significantly related to the occurrence and distribution of EDCs in the lakes. Risk assessment demonstrated that the occurrence of EDCs posed minimum to medium risk to aquatic organisms in the lakes. The results showed that the lakes faced a threat hormone pollution though it was at lower doses and, thus, the ecological risk of EDCs should be considered in future environmental policies and decisions in China.

Occurrence, distribution, and risk assessment of bisphenol analogues in Luoma Lake and its inflow rivers in Jiangsu Province, China

Bisphenol analogs (BPs) are widely used in industrial and commercial products and have been detected in surface water, sediment, sewage, and sludge. The presence of BPs in the natural environment poses threats to the aquatic ecosystem and human health. The concentration, distribution, seasonal variation, and risk assessment of BPA and BPA structural analogs including BPB, BPF, BPS, BPZ, BPAF, and BPAP in surface water and sediment during dry season and flood season in Luoma Lake and its inflow rivers in Jiangsu Province, China, were investigated in this study. The detection frequency of BPA and BPF was 100%. Although the use of BPA is restricted, BPA is still the dominant BPs in surface water and sediment. The concentration of BPs in surface water during flood season was higher than that in dry season. The concentrations of BPs in Fangting River, Zhongyun River, and Bulao River were higher than those in Luoma Lake. The average concentrations of BPs in surface water were in the order of BPA > BPF> BPS> BPB > BPZ > BPAF> BPAP. Compared with other studies, the concentration of BPs in Luoma Lake was moderate. There is no significant spatial distribution and difference in seasonal variation of BPs concentration in sediment (p > 0.05). Compared with other studies, the contamination of BPs in sediment of Luoma Lake was relatively low. Risk quotient (RQ) was used to evaluate the ecological risk of BPs in water environment, and the 17β estradiol equivalent (EEQ) method was used to estimate the estrogenic activity of BPs. The risk assessment showed no high ecological risk (RQ < 1.0) and estrogenic risk (EEQ < 1.0 ng/L) in dry season and flood season. The estimated RQ and EEQ_t indicated that the ecological and human health impacts were negligible in the short term.

Adverse effects of bisphenol B exposure on the thyroid and nervous system in early life stages of zebrafish

Bisphenol B (BPB), a widely used alternative of bisphenol A (BPA), has been detected in various environmental media and foodstuffs. However, the knowledge of the health risks about BPB is still limited. In this study, the effects of BPB on thyroid hormone homeostasis and neuronal development were evaluated by exposure of embryos 2 h post-fertilization (hpf) to BPB (0, 1, 10, 100 and 1000 μg/L) until 144 hpf. The results showed that 100 and 1000 μg/L BPB exposed larvae exhibited abnormal morphologies in phenotype and brain histological patterns. Significant decline of thyroid hormone thyroxine (T4) content and elevation of 3,5,3'-triiodothyronine (T3) content, along with the up-regulated expression of tg, trhr1, dio1, dio2, thrα, thrβ genes and down-regulated expression of tsh, ttr and trh genes in BPB exposed zebrafish larvae were observed. Moreover, locomotor activity of larvae was decreased, and the transcription of genes (e.g., elavl3, gap43, zn5, α-tubulin, syn2a and mbp) related to neuronal development were inhibited after exposure to BPB. The mechanism of neurotoxicity and thyroid disruption in zebrafish larvae induced by BPB were discussed.

Bisphenol A disrupts apolipoprotein E expression through estrogen-related receptor gamma and DNA methlylation in the liver of male rare minnow Gobiocypris rarus

An increasing number of studies show that bisphenol A (BPA) can cause lipid metabolism disorder. However, few studies focused on the effect of BPA on lipid transport. Apolipoprotein E (ApoE) plays important roles in triglyceride (TG) transportation. Our previous study found that ApoE was a sensitive gene in response to BPA exposure in male rare minnow. To investigate the effect and mechanism of BPA on hepatic ApoE, adult male rare minnow Gobiocypris rarus were exposed to environmentally relevant concentrations of BPA (15 μg/L) for 1, 3 and 5 weeks. Results showed that BPA inhibited ApoE expression at week 1 and 5, while induced its expression at week 3. A positive estrogen-related receptor gamma (Esrrg) response element was identified in the promoter region of ApoE. The change of the Esrrg recruitment was consistent with ApoE mRNA expression. Moreover, the methylation status of the CpG sites near and on the Esrrg binding sites changed opposite to the ApoE mRNA level, which may be the main cause for the change in Esrrg recruitment. The expression of ApoE protein was significantly enhanced following long-term BPA exposure. Consistently, the TG accumulation was significantly increased in the plasma. The present study demonstrates that BPA could affect rare minnow ApoE expression, which is probably one of the ways for BPA disturbing fish lipid metabolism.

Bisphenol A regulates apolipoprotein A1 expression through estrogen receptors and DNA methlylation and leads to cholesterol disorder in rare minnow testis

Bisphenol A (BPA) is a well-known plasticizer that widely distributed in the aquatic environment. BPA has many adverse effects on reproduction. However, few studies have investigated the mechanism of BPA affecting reproduction from the perspective of lipid metabolism. Apolipoprotein A1 (ApoA1) is the major component of high-density lipoprotein (HDL), and plays critical roles in reverse cholesterol transport (RCT). In this study, in order to investigate the effect and molecular mechanism of BPA on testicular ApoA1 and the role of ApoA1 in BPA induced abnormal spermatogenesis, adult male rare minnow Gobiocypris rarus were exposed to 15 μg/L of BPA for 1, 3 and 5 weeks. Results showed that BPA could significantly affect testicular ApoA1 mRNA and protein levels, testicular cholesterol levels, plasmatic sex hormone levels and the integrity of sperm head membrane. The main mechanism of BPA regulating ApoA1 expression is to alter Esr recruitment and CpG sites DNA methylation in ApoA1 promoter. The induced ApoA1 up-regulated high density lipoprotein cholesterol levels and enhanced RCT, and finally decreased the testicular free cholesterol levels. This is likely a key mechanism by which BPA induces sex hormone disorder and sperm head membrane damage. The present study reveals the mechanism by which BPA interferes with spermatogenesis from the perspective of cholesterol transport.

Transformation of bisphenol AF by chlorination: kinetic study and product identification

Bisphenol AF (BPAF), commonly used as a substitute for bisphenol A (BPA), is also an endocrine disruptor with cytotoxicity, neurotoxicity, genotoxicity, and biotoxicity. In this study, we found that BPAF could be effectively degraded by free chlorine. The second order rate constant of the reaction ranged from 1.67 to 126.67 M^-1·s^-1 in the pH range of 5.0-11.0. Nineteen products were detected by LC-Q-TOF-MS analysis, including chlorinated BPAF (i.e., mono/di/tri/tetrachloro-BPAF), 8 dimers, and 6 trimers. According to the identified products, two transformation pathways of electrophilic substitution and electron transfer are proposed. Humic acid (HA) could inhibit the degradation rate of BPAF due to its ability to reduce the reactive BPAF radical intermediates to the parent compound. The addition of low concentrations of Br^- and I^- accelerates the reaction rate of BPAF, due to the formation of HOBr and HOI with a higher oxidizing capacity. In seawater, BPAF degraded rapidly, and 16 new halogenated products were formed. Theoretical calculation shows that electrophilic substitution is more prone to occur at the ortho position of the hydroxyl group to form chlorinated products, while electron transfer tends to occur at the hydroxyl oxygen, resulting in the formation of BPAF radical and its subsequent coupling products.

The occurrence of selected endocrine-disrupting chemicals in water and sediments from an urban lagoon in Southern Italy

Endocrine-disrupting chemicals (EDCs) are agents able to exert perturbation toward the endocrine system via a broad array of signalling pathways. Some EDCs are released into the environment as a result of antropogenic activities. Analytical surveillance plays a critical role in investigating the prevalence of such chemicals in environmental samples. A study was carried out in a lagoon in Southern Italy, a water basin relates to the sea through a mouth channel, making this water body a "dynamic environment". The screening of fourteen EDCs in surface waters and sediments, includes a fast and cost-effective sample preparation, based on a solid-liquid (sediments) and liquid-liquid (surface waters) extraction and a chromatographic analysis by liquid chromatography tandem UV and fluorescence detection. Only four chemicals out the fourteen investigated EDCs were detected in both matrices with a frequency higher than 60%. The average concentrations of the single EDC were higher in sediments (730-155.000 ng kg^-1  dw) than in surface waters (132-28.000 ng L^-1 ). Limited to the assayed EDCs, the ecosystem has a low risk regarding to the conservation of biodiversity of the animal species living thereby, since the total estrogenic activity does not exceed 1 ng L^-1 . PRACTITIONER POINTS: Occurrence of selected EDCs was investigated in an Italian lagoon in Southern Italy. BPAF, BADGE, and BPA were the most frequently and highly detected compounds in both waters and sediments. Concentration levels were greater in the sediment than in water samples. Low risk for the ecosystem biodiversity concerning investigated EDCs.

Bisphenol A and its analogues in outdoor and indoor air: Properties, sources and global levels

Bisphenol A (BPA) and its analogues are high-volume production organic synthetic compounds used in the synthesis of plastics. BPA has been categorized as an endocrine disrupting compound due to its ability to disrupt the hormonal makeup of living organisms. Air and dust are common sources of exposure of BPA for living organisms and most sources are anthropogenic and a result of thermal destruction of BPA containing materials, import and export of recyclable materials (especially e-waste) and fugitive emissions near BPA handling facilities. Current reports on BPA levels in air are limited and focused on effluent and surface water analysis (due to BPA's propensity for environmental distribution to water). BPA's presence in the developing part of the world is of particular concern due to lack of regulations and uncontrolled incinerations of domestic and imported waste. The current review summarizes up-to-date scientific literature on BPA's occurrence in air, alongside physico-chemical and partitioning properties, persistence in air, seasonal variation, consideration of analytical strategies for BPA analysis and toxicological information. Globally reported air concentrations of BPA are included in this report, alongside reports on indoor air concentration of BPA and its analogues. As a special interest, levels of tetrabromobisphenol (TBBPA) are also mentioned. Overall, the highest outdoor air levels of BPA were reported in China (1.1 × 106 pg/m3) near a low-tech e-waste recycling site, while examination of indoor dust revealed the presence of bisphenol analogues used in "BPA-free" products, raising questions about their safety. Due to their low volatility, BPA and its analogues are mainly present in air associated with particles; this has important implications for their persistence in air and the role of particulate matter (especially microplastics) in their transport and deposition. Current understanding of BPA's particle association is limited, hence studying its potential for heterogeneous oxidative transformations is a pressing need required for accurate accounting of potential risk to human health and the environment.

Occurrence of antibiotics and antibiotic resistance genes and their correlations in river-type drinking water source, China

The occurrence and distribution of antibiotics and antibiotic resistance genes (ARGs) in natural water has attracted worldwide attention. Antibiotic and ARG pollution in the surface water of drinking water sources might directly/indirectly affect human health. In this study, the distribution of 38 antibiotics, 10 ARGs, 2 integrons, and 16S r DNA in river-type water sources in a large city of China were monitored in winter, which was a period with high level of antibiotic pollution. The results showed that 20 antibiotics were detected with different detection frequencies. The antibiotic pollution in December 2019 was relatively high, with the total concentrations of antibiotics ranging from 281.95 to 472.42 ng/L, followed by that in January 2020 (191.70-337.29 ng/L) and November 2019 (161.25-309.72 ng/L). Sulfacetamide was dominant in November 2019 (23.52-219.00 ng/L) and in January 2020 (113.18-209 ng/L), while norfloxacin in December 2019 (146.72-290.20 ng/L). All the target antibiotics posed low or medium risk for aquatic organisms, and posed low health risk for mankind. Sul1 and erm36 were the predominant ARGs, and intI1 was the predominant integron in drinking water sources. Only tetA showed positive correlations with its corresponding antibiotic (tetracycline). The rest of ARGs showed no correlations with antibiotics or positive / negative correlations with their non-corresponding antibiotics. Overall, the antibiotics and ARG pollution in these water sources was relatively low. These findings provided some reference data for the distribution of antibiotics and ARGs in river-type drinking water sources of large cities in China.

[Advances in solid-phase extraction for bisphenols in environmental samples]

双酚类化合物作为一类内分泌干扰物广泛存在于环境介质中,经过多种途径迁移至人体后,可对人体产生内分泌毒性、细胞毒性、基因毒性、生殖毒性、二噁英毒性和神经毒性,已被加拿大政府风险评估识别为进一步优先控制名录。随着环境领域对双酚类化合物的广泛关注,相关研究工作逐渐向水、沉积物、灰尘和生物样品等多介质开拓。但是,由于不同环境样品在基质复杂性和污染物浓度水平等方面存在显著差异,开发提取效率高、净化选择性好、普适性强、操作简单、高通量的提取和净化方法,有助于实现环境介质中双酚类化合物的高灵敏、批量检测。近年来,新型前处理技术发展迅速,尤其是固相萃取技术,在双酚类化合物提取与净化方面取得了长足的发展,不仅在一定程度上克服了传统提取净化方法存在的耗时、耗力和耗溶剂等不足,而且为新型污染物分析提供了更多的技术支持。该文简述了典型双酚类化合物的理化性质、用途用量和环境危害,重点围绕新型固相萃取吸附剂开发和固相萃取模式转变两个方面,总结了固相萃取在双酚类化合物提取净化方法方面取得的进展。商品化固相萃取产品普适性强,在环境监测领域应用范围较广,适用于双酚类化合物的产品种类有限;新型吸附剂研发聚焦吸附容量(如介孔硅材料、碳纳米材料、金属-有机框架材料、环糊精)和选择性(如分子印迹聚合物和混合模式离子交换聚合物)两个方面,种类多样化可满足不同检测需求;越来越多的高灵敏分析仪器不断推向市场,为适应新的发展形势,固相萃取模式正逐渐向微型化、自动化、简易化等方向发展,如QuEChERS、固相微萃取、磁固相萃取等。

Cross-linked FeCl3-activated seaweed carbon/MCM-41/alginate hydrogel composite for effective biosorption of bisphenol A plasticizer and basic dye from aqueous solution

A FeCl₃-activated seaweed carbon/MCM-41/alginate hydrogel composite (ECAC/MCM-41/ ALG) cross-linked with calcium chloride (2% CaCl₂) was synthesized for the biosorption of bisphenol A (BPA) plasticizer and basic blue (BB) dye. Biosorption uptakes of BPA and BB were performed in a batch mode with varying solution pH from 3 to 11, initial sorbate concentration from 25 to 300 mg/L, reaction time from 0 to 10 h, and biosorption temperature from 30 to 50 °C. The maximum BPA and BB uptake mechanisms were fast, which occurred within contact times of 1 and 2 h with monolayer coverage capacities of 222.32 and 190.11 mg/g at 50 °C, respectively. Cyclic biosorption/desorption behavior was evaluated via an ethanol elution to evaluate the feasibility of the ECAC/MCM-41/ALG for long-term application. Results revealed the biosorption renewability for five cycles up to 80% of the newly synthesized hydrogel composite for the purification of industrial wastewater laden with emerging contaminants.

Emerging endocrine disruptors in two edible fish from the Persian Gulf: Occurrence, congener profile, and human health risk assessment

The occurrence of endocrine disrupting chemicals (EDCs) has been determined in two widely consumed fish species from Persian Gulf i.e., Epinephelus coioides and Platycephalus indicus by applying a validated analytical for the simultaneous detection of fourteen EDCs. The concentrations of all detected EDCs were greater in the liver than in the muscle (except for bisphenol A in P. indicus), suggesting a prolonged exposure of the fishes to these pollutants in the Persian Gulf. Specifically, the results showed that di (2-ethylhexyl) phthalate (DEHP) was the compound detected most frequently and at the highest concentration in both species. DEHP levels in ranged from 6.68 to 297.48 μg g-dw^-1 and from 13.32 to 350.52 μg g-dw^-1, in muscle and in liver, respectively. A risk assessment study was conducted, and demonstrated that consuming two fish based- meals per week may result in a moderate risk especially for vulnerable population groups.

Risk assessment and investigation of landfill leachate as a source of emerging organic contaminants to the surrounding environment: a case study of the largest landfill in Jinan City, China

Emerging organic contaminants (EOCs) have been widely studied in landfill leachates but not in the surrounding environment of landfills. In this study, two sampling campaigns were conducted to determine 45 EOCs in landfill leachates and environmental samples near a landfill in East China. Our study focused on the seasonal occurrence and spatial distribution of the target EOCs, as well as their ecological risks. The results showed 13 out of 45 EOCs were detectable and achieved individual concentrations that ranged from 2.0 to 5080 ng/L in the landfill leachates. Most of the detected EOCs exhibited higher concentrations in the leachates collected in summer than in winter. Effective removal of the EOCs by a two-stage disc tube reverse osmosis (DTRO) system led to a significant reduction in their concentration levels (< LOQ ~ 49 ng/L) in treated leachates. Eight EOCs (< LOQ ~ 62.7 ng/L) were detected in the groundwater adjacent to the landfill and had a similar composition pattern to raw leachates. The contamination levels of the target EOCs in groundwater decreased with the distance of sampling sites from the landfill. In soil samples, the occurrence of target EOCs was not consistent with raw or treated landfill leachates. Spatially, no apparent difference in the EOC concentrations was observed in the soil nearby the landfill. Crop plants sorbed the EOCs contained in soil (< LOQ ~ 30.4 ng/L), but they were not able to bioconcentrate the contaminants in either roots or edible parts. Risk assessment suggested that the individual EOC likely posed medium to high risks to aquatic organisms in groundwater while negligible impacts to human health through consumption of vegetables. To the best of our knowledge, this is the first report on the contribution of landfill leachates to EOC contamination in both aquatic and soil environments in East China. Our findings emphasized the importance of investigating EOCs in landfill leachates and accumulative environmental risks of EOCs in the neighboring environment of landfills in China.

Determination of estrogens and estrogen mimics by solid-phase extraction with liquid chromatography-tandem mass spectrometry

An analytical method has been developed and validated for the determination of six estrogens and estrogen mimics, namely estriol (E3), bisphenol A (BPA), 17β-estradiol (E2), estrone (E1), ethynyl estradiol (EE2) and dienestrol (DIE), with frequent occurrence in the natural environment. Solid phase extraction coupled with liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) using electrospray ionization (ESI) in a negative mode was applied to concentration, identification, and quantification of estrogens and estrogen mimics. The SPE conditions were optimized as the selection of C18 as cartridges and MeOH as an eluent, and the control of solution pH at 9.0. The method was validated by satisfactory recoveries (80-130%) and intra-day and inter-day precision (<18.4%, as relative standard deviation), and excellent linearity for calibration curves (R² > 0.996). The limits of detection (LODs) for six target estrogenic compounds ranged between 2.5 and 19.2 ng/L. The effects of matrix background on the determination were evaluated in terms of LODs, LOQs, analyte recovery, and slopes of calibration curves in five different water matrices. Matrix effects by tap water were negligible. However, both matrix suppression and enhancement (i.e., E3, E1, DIE) were observed in surface water and wastewater. The positive correlation between LODs and TOC in various water matrices indicated the negative effect of organic pollutants on the method sensitivity. The sum of target estrogenic compounds in environmental samples were within 17-9462 ng/L.

The sinking behavior of micro-nano particulate matter for bisphenol analogues in the surface water of an ecological demonstration zone, China

Bisphenol analogues (BPs) have been widely used in industrial production as substitutes of bisphenol A (BPA). The demand and production of BPs are growing rapidly in China. In this study, the pollution levels and distribution characteristics of five BPs were investigated in surface water from rivers located in different land-use types of an ecological demonstration zone. All BPs were detected at least once in the traditionally dissolved phase, colloidal phase and suspended particulate matter (SPM) with the mean total concentrations of 465.1 ng L-1, 114.4 ng L-1 and 11.3 μg g-1 dry weight, respectively. BPA is the dominant BP in the traditionally dissolved phase and colloidal phase, with the mean contribution rates of 77.6% and 70.7%, respectively, followed by bisphenol F (BPF) and/or bisphenol S (BPS). The colloids as the important sinks of contaminants contributed 42.3% of bisphenol Z, 37.3% of BPF, 24.9% of BPA, 22.3% of BPAF and 18.4% of BPS in the traditionally dissolved phase. However, BPA alternatives are found primarily in the SPM, in which the contribution rate of BPA ranges from 0.6% to 48.1%, with the mean contribution of 12.4%. Based on BP concentrations in the traditionally dissolved phase, moderate ecological risk levels of BPA and BPF towards aquatic organisms were posed. Fish and/or algae are the most sensitive aquatic organisms, and hence chronic toxicological effects should not be ignored especially in fish.

Occurrence and Fate of Bisphenol A and its Congeners in Two Wastewater Treatment Plants and Receiving Surface Waters in Romania

The present study investigated the distribution and environmental fate of Bisphenol A (BPA), the 4-hydroxyacetophenone (4-HAP) metabolite, and 5 other bisphenol congeners in 2 municipal wastewater treatment plants (WWTPs) and their receiving rivers in Romania. Accordingly, a new, highly sensitive and accurate solid-phase extraction-liquid chromatography-electrospray ionization-tandem mass spectrometry method was developed and validated. This technique generated low limit of quantitation values: below 2.3 ng/L for surface water and less than 2.4 and 2.7 ng/L for WWTP effluent and influent water. The sum of detected analytes in wastewater was between 1337 and 16 118 ng/L for influent samples and between 15 and 96 ng/L for effluent samples. In surface water, the total of all compounds was somewhere between 34 and 240 ng/L. The highest concentration observed was for BPA in all 3 types of analyzed water (up to 9140 ng/L for influent, as high as 75 ng/L for effluent, and a maximum of 135 ng/L in surface waters). All analyzed samples were free of bisphenols B, C, and F. For all analytes detected in surface water, the concentration values were higher than those determined in the effluent samples, which may be caused by intrinsic contamination of the 2 rivers (Danube and Jiu Rivers). Values of environmental risk coefficients, calculated for both effluents and surface waters, indicated a low ecological risk or no ecological risk for 3 types of organisms (algae, daphnia, and fish). Human risk assessment calculation suggests no risk to human health as a result of the presence of BPA in either of the 2 rivers. Environ Toxicol Chem 2021;40:435-446. © 2020 SETAC.

Cumulative health risks for bisphenols using the maximum cumulative ratio among Chinese pregnant women

Bisphenol A and its alternatives are frequently detected in environmental and human samples, but studies associated with the pattern of combined health hazards from the exposure to the bisphenol mixtures are lacking, particularly for pregnant women. Here, we recruited 941 pregnant women with a full set of urine samples in the three trimesters collected under a cohort study project in Wuhan, China, between 2014 and 2015. We measured the concentrations of 8 bisphenols in 2823 urine samples, and calculated the average concentrations of bisphenols, which were detected in over 50% of samples, once during each trimester of pregnancy. We calculated the maximum cumulative ratio (MCR) on basis of estimated daily intake (EDI), hazard quotient (HQ), hazard index (HI) of three major bisphenols, including bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), to find which one or mixtures drive risks. Participants were categorized into four groups according to their maximum HQ, HI and MCR values. We found negative relationships between log(MCR-1) and log(HI) with the slope (-0.6431). Percentage of HQ of BPA in HI ranged from 37.1% (<25th percentiles of HI) to 75.5% (>95th percentiles of HI) indicating the upward trend of dominance by BPA at increasing HI ranges. The cumulative health risks of bisphenol exposures largely originated from the health hazards of BPA and BPS, particularly BPA. The intervention for regulation on the production and application of BPA and its alternatives are urgent, and China should consider national regulation on these chemicals based on its risk to human health.