Human health risk on environmental exposure to Bisphenol-A: a review

Prenatal Bisphenol A Exposure in Mice Induces Multitissue Multiomics Disruptions Linking to Cardiometabolic Disorders

The health impacts of endocrine-disrupting chemicals (EDCs) remain debated, and their tissue and molecular targets are poorly understood. In this study, we leveraged systems biology approaches to assess the target tissues, molecular pathways, and gene regulatory networks associated with prenatal exposure to the model EDC bisphenol A (BPA). Prenatal BPA exposure at 5 mg/kg/d, a dose below most reported no-observed-adverse-effect levels, led to tens to thousands of transcriptomic and methylomic alterations in the adipose, hypothalamus, and liver tissues in male offspring in mice, with cross-tissue perturbations in lipid metabolism as well as tissue-specific alterations in histone subunits, glucose metabolism, and extracellular matrix. Network modeling prioritized main molecular targets of BPA, including Pparg, Hnf4a, Esr1, Srebf1, and Fasn as well as numerous less studied targets such as Cyp51 and long noncoding RNAs across tissues, Fa2h in hypothalamus, and Nfya in adipose tissue. Lastly, integrative analyses identified the association of BPA molecular signatures with cardiometabolic phenotypes in mouse and human. Our multitissue, multiomics investigation provides strong evidence that BPA perturbs diverse molecular networks in central and peripheral tissues and offers insights into the molecular targets that link BPA to human cardiometabolic disorders.

Temporal and Spatial Distributions of Bisphenol A in Marine and Freshwaters in Turkey

Bisphenol A (BPA), a chemical component used in the manufacture of plastics, is commonly introduced to and detected in aquatic environments. This is the first study conducted to understand the distribution of BPA in the marine and freshwaters of Turkey. The purpose of this study is to report BPA concentrations measured from a time-series conducted in coastal waters of Erdemli and regional rivers located in the northeastern Mediterranean region. Furthermore, seawater samples obtained from other Turkish coastal areas-The Black Sea, Bosphorus, Sea of Marmara, and the Mediterranean Sea-also were investigated to gain a better understanding of regional and seasonal variations of BPA concentrations in Turkish Seas. Whilst spatial variation in BPA concentrations was very low, temporal variation was found to be high. It has been shown that BPA can reach the deep sea environment (> 500 m depth). This study indicated that BPA contamination has reached serious levels at another location in the world.

Application of pea-like yolk–shell structured Fe3O4@TiO2 nanosheets for photocatalytic and photo-Fenton oxidation of bisphenol-A

Uniform pea-like yolk–shell (PLYS) structured magnetic TiO₂(PLYS-Fe₃O₄@TiO₂) nanosheets have been prepared via a combined kinetics-controlled mechanical force-driven and hydrothermal etching assisted crystallization method and characterized.

A synthetic strategy toward isosorbide polycarbonate with a high molecular weight: the effect of intermolecular hydrogen bonding between isosorbide and metal chlorides

Isosorbide polycarbonate (ISB-PC) was prepared by melt transesterification and polycondensation reaction by employing ISB and diphenyl carbonate (DPC) as monomers.

Influence of gastrointestinal tract on metabolism of bisphenol A as determined by in vitro simulated system

Oral exposure is a major route of human bisphenol A (BPA) exposure. However, influence of gastrointestinal tract on BPA metabolism is unavailable. In this study, in vitro simulator of the human intestinal microbial ecosystem (SHIME) was applied to investigate the changes in bioaccessibility and metabolism of BPA in different parts of gastrointestinal tract (stomach, small intestine and colon). Then the human hepatoma cell line HepG2 was employed to compare toxic effects of BPA itself and effluents of SHIME system on hepatic gene expression profiles. Results showed that level of bioaccessible BPA decreased with the process of gastrointestinal digestion. But the gastrointestinal digestion could not completely degrade BPA. Then, BPA exposure significantly changed microbial community in colons and increased the percentage of microbes shared in ascending, transverse and descending colons. Abundances of BPA-degradable bacteria, such as Microbacterium and Alcaligenes, were up-regulated. Further, SHIME effluents significantly up-regulated expressions of genes related to estrogenic effect and oxidative stress compared to BPA itself, but reduced or had little change on the risk of cell apoptosis and fatty deposits. This study sheds new lights on influence of gastrointestinal digestion on bioaccessibility and toxic effects of BPA.

Exposure to Bisphenol A, Bisphenol F, and Bisphenol S in U.S. Adults and Children: The National Health and Nutrition Examination Survey 2013-2014

Bisphenol F (BPF) and bisphenol S (BPS) are replacing bisphenol A (BPA) in the manufacturing of products containing polycarbonates and epoxy resins. Data on current human exposure levels of these substitutes are needed to aid in the assessment of their human health risks. This study analyzed urinary bisphenol levels in adults (N = 1808) and children (N = 868) participating in the National Health and Nutrition Examination Survey (NHANES) 2013-2014 and investigated demographic and lifestyle factors associated with urinary levels of bisphenols. BPA, BPS, and BPF were detected in 95.7, 89.4, and 66.5% of randomly selected urine samples analyzed as part of NHANES 2013-2014, respectively. Median levels of BPA in U.S. adult were higher (1.24 μg/L) than BPF and BPS levels (0.35 and 0.37 μg/L, respectively). For children, median BPA levels were also higher (1.25 μg/L) than BPF and BPS levels (0.32 and 0.29 μg/L, respectively). The limits of detection for BPA, BPF, and BPS were 0.2, 0.2, and 0.1 μg/L, respectively. Urinary levels showed associations with gender, race/ethnicity, family income, physical activity, smoking, and/or alcohol intake that depended on the specific bisphenol. The results of this study indicate that exposure of the general U.S. population to BPA substitutes is almost ubiquitous. Because exposures differ across the U.S. population, further studies of environmental, consumer, and lifestyle factors affecting BPF and BPS exposures are warranted.

Bacteria enhanced lignocellulosic activated carbon for biofiltration of bisphenols in water

There are eight bisphenol analogues being identified and characterized; among them, bisphenol A (BPA) is on the priority list on the basis of its higher level of uses, occurrence, and toxicity. The endocrine system interfered by BPA has been inventoried as it has the same function as the natural hormone 17β-estradiol and binds mainly to the estrogen receptor (ER) to exhibit estrogenic activities. The BPA concentration in surface waters (14-1390 ng/L) in many parts of the world, such as Japan, Korea, China, and India, was also a significant concern. Research efforts are focusing on restricting BPA consumption as well as removing BPA in our environment especially in drinking water. Current opinion is that lignocellulosic activated carbon stimulated with BPA-degrading bacteria could have the potential to provide solution for recent challenges faced by water utilities arising from BPA contamination in water. This technology has some new trends in the low-cost biofiltration process for removing BPA. This review is to provide in-depth discussion on the fate of BPA in our ecosystem and underlines methods to enhance the efficacy of activated carbon in the presence of BPA-degrading bacteria in the biofiltration process.

The state of bisphenol research in the lesser developed countries of the EU: a mini-review

Bisphenol compounds are a class of chemical epoxy resins that are found throughout the world in food packaging, thermal paper products, dental materials, and more. These compounds were deemed to be safe until recently, when some studies noticed adverse effects at very low doses, due to the fact that bisphenol acts as an endocrine disruptor. Over the last ten years, studies have been performed to detect bisphenols (especially BPA) in serum and blood samples throughout the world. Essentially, the majority of the earth's population seems to have significantly measurable levels of bisphenol in their blood plasma or urine. However, the majority of the population is unaware that a potential danger may exist. The purpose of this mini-review is to report upon the state of bisphenol research in the lesser developed member-states of the European Union and to increase awareness of the exposure level and possible adverse health effects of this endocrine disruptor. The results show that only three of the most newly admitted members of the European Union have published research concerning the health effects and/or environmental exposure of EU citizens to bisphenol compounds. Those countries were Slovenia, Poland and the Czech Republic. The rest of the surveyed member-states had little or no published research in relation to bisphenol compounds. Furthermore, even the three nations referred to above still lagged far behind the more advanced EU member-states. The lack of research could translate into a lack of awareness amongst the citizenry of nearly half of the EU, and may be unnecessarily putting those EU citizens at an increased risk of exposure.

Low concentration of BPA induces mice spermatocytes apoptosis via GPR30

Bisphenol A (BPA) acts as xenoestrogen and has a great impact on disorders of human reproductive system. However, the mechanism through which BPA can affect human testicular function remains to be identified. GPR30 is a novel membrane estrogen receptor with high-affinity and low-capacity binding to estrogens. We demonstrated that estrogen receptor α (ERα), estrogen receptor β (ERβ) as well as GPR30 are expressed in mouse spermatocyte-derived GC-2 cells using Real-time PCR. We treated the cells with different doses of BPA and found that even low doses of BPA can inhibit GC-2 cell growth using MTT assay. To make sure which receptor is responsible for the biological function of BPA, we used ER down-regulator ICI and indicated that BPA could bind to GPR30. We also observed that BPA was able to induce Erk1/2 phosphorylation in GC-2 cells and proved that this process was mediated by GPR30-related EGFR-MAPK pathway using western blot. By Real-time PCR, we found that the expression of c-Fos was up-regulated and Cyclin D1 gene was down-regulated, in the presence of BPA and ICI. The results of MTT assay, comet assay and flow cytometry indicated that the activation of GPR30 induced by BPA inhibited the cell growth and induced cell apoptosis and ICI, GPR30 siRNA, EGFR inhibitor (AG), and MAPK (PD) inhibitor could partially reverse this effect. Immunohistochemistry on the testis of BPA -damaged mice showed that BPA induced spermatocyte apoptosis without affecting the seminiferous tubules and spermatocyte. In conclusion, BPA triggered spermatocyte apoptosis via GPR30.

Phosphorus flame retardants and Bisphenol A in indoor dust and PM2.5 in kindergartens and primary schools in Hong Kong

Organophosphate flame retardants (PFRs) and bisphenol A (BPA) were measured in indoor dust and PM_2.5 samples from nine kindergartens and two primary schools in Hong Kong. The average levels of PM_2.5 ranged from 4.0E+03 ng/m³ to 1.5E+04 ng/m³. Average levels of PFRs (from 1.5 ng/m³ to 20 ng/m³ in PM_2.5; from 8.0E-02 μg/g dw to 2.4 μg/g dw in dust) and BPA (from 6.4E-01 ng/m³ to 1.0 ng/m³ in PM_2.5; from 1.0E-02 μg/g dw to 2.0E-01 μg/g dw in dust) were detected in most of the sampling sites. Tri-(2-Chloroethyl) phosphate (TCEP), tris(1,3-Dichloro-2-propyl) phosphate (TDCP), tris-(chloroisopropyl) phosphate (TCPP), and triphenyl phosphate (TPHP) were present in low levels in PM_2.5 with medians of 16, 14, 8.7, and 3.2 ng/m³, respectively. In dust, the medians were 1.5E-01, 5.5E-02, 5.9E-01, 8.6E-01, and 8.5E-02 μg/g dw for TCEP, TCPP, TDCPP, TPHP, and 2-ethylhexyl diphenyl phosphate, respectively. The medians of BPA were 6.4E-01 ng/m³ and 7.4E-02 μg/g dw for PM_2.5 and dust, respectively. A positive correlation was found between indoor PM_2.5 and dust in the levels of TCEP (r = 0.85; p = .05). In the individual classroom in this survey, the predominant PFRs were similar, that is, TDCP and TCEP in indoor PM_2.5 while TPHP and TDCP in dust. TPHP and TCEP in primary schools were obviously lower than those in kindergartens. The estimated daily intakes via PM_2.5 and dust for all selected PFRs ranged from 1.3E-4 μg/kg/d to 2.0E-02 μg/kg/d, and the value of less than the detection limit at 3.5E-4 μg/kg/d was found for BPA. The EDI values of TPHP in dust non-dietary intake fraction were higher than those in the others. Calculated hazard indices (EDI/RfD) ranged from 4.8E-06 and 5.5E-03, showing that PFRs and BPA in PM_2.5 and dust presented no health risks to children.

Elaboration of bio-epoxy/benzoxazine interpenetrating polymer networks: a composition-to-morphology mapping

Real interpenetrating polymer networks obtained from the sequential polymerization of epoxy and benzoxazine networks, with highly improved mechanical properties.

Bisphenol A induces cell cycle arrest in primary and prostate cancer cells through EGFR/ERK/p53 signaling pathway activation

Bisphenol A (BPA) belongs to the class of chemicals known as endocrine disruptors and has been also involved in the pathogenesis and progression of endocrine related cancer such as breast and prostate cancers. Here, we have investigated the effect of BPA in human prostate cancer LNCaP cells and in human non-transformed epithelial prostate EPN cells. Our data showed that BPA induces the down regulation of cyclin D1 expression and the upregulation of the cell cycle inhibitors p21 and p27, leading to cell cycle arrest. Interestingly, we found that the BPA anti-proliferative response depends on a strong and rapid activation of epidermal growth factor receptor (EGFR), which stimulates ERK-dependent pathway. This, in turn, induces expression of p53 and its phosphorylation on residue Ser15, which is responsible for cell cycle arrest. EGFR activation occurs upon a cross talk with androgen (AR) and estradiol receptor-β (ERβ) which are known to bind BPA.

Altogether, these findings show a novel signaling pathway in which EGFR activation plays a key role on BPA-induced cell cycle inhibition through a pathway involving AR and ERβ/EGFR complexes, ERK and p53. Our results provide new insights for understanding the molecular mechanisms in human prostate cancer. On the other, they could allow the development of new compounds that may be used to overcome human prostate cancer resistance to endocrine therapy in promising target therapeutic approaches.

Bisphenol A Causes Liver Damage and Selectively Alters the Neurochemical Coding of Intrahepatic Parasympathetic Nerves in Juvenile Porcine Models under Physiological Conditions

Bisphenol A (BPA) is an extremely common polymer that is used in typical everyday products throughout the world, especially in food and beverage containers. Within the last ten years, it has been found that the BPA monomer tends to leach into foodstuffs, and nanogram concentrations of it may cause a variety of deleterious health effects. These health problems are very evident in developing children and in young adults. The aim of this study was to expose developing pigs to dietary BPA at both legally acceptable and ten-fold higher levels. Livers that had been exposed to BPA showed vacuolar degeneration, sinusoidal dilatation, vascular congestion and glycogen depletion that increased with exposure levels. Furthermore, the livers of these models were then examined for irregularities and double-labeled immunofluorescence was used to check the innervated hepatic samples for varying neuronal expression of selected neuronal markers in the parasympathetic nervous system (PSNS). It was found that both the PSNS and all of the neuronal markers showed increased expression, with some of them being significant even at recommended safe exposure levels. The implications are quite serious since these effects have been observed at recommended safe levels with expression increasing in-line with exposure levels. The increased neuronal markers studied here have been previously correlated with behavioral/psychological disorders of children and young adults, as well as with childhood obesity and diabetes. However, further research must be performed in order to develop a mechanism for the above-mentioned correlations.

Relationship between dietary factors and bisphenol a exposure: the second Korean National Environmental Health Survey (KoNEHS 2012-2014)

Background

This study was aimed at finding out the exposure level of bisphenol A (BPA), a well-known endocrine disruptor, in relation to dietary factors using a data representing the Korean general population.

Methods

This study was performed on 5402 adults aged 19 years and older based on the Second Korean National Environmental Health Survey (KoNEHS 2012–2014). The data analyzed urinary BPA concentration in relation to socio-demographic variables, health behavior-related variables, and dietary factor-related variables. Odds ratio (OR) was calculated through a logistic regression analysis after dividing the participants into high BPA exposure group and low BPA exposure group based on the top 75 percentile concentration. The logistic regression analysis was carried out considering the appropriate sample weight, stratification, and clustering of the second KoNEHS sample design.

Results

The group drinking bottled water at home and the group using zip-top bags/plastic bags showed significantly higher urinary BPA concentration in female. OR tends to increase as the intake frequency of frozen food increased and OR of frozen food consumption of more than once a week was 1.48 (95% confidence interval (CI) 1.02–2.24) for male and the group drinking bottled water showed significantly higher OR of 1.45 (95% CI 1.06–2.17) after adjusting the related factors for female.

Conclusions

BPA levels were high in female using bottled water and in male consuming frozen food, and therefore bottled water and frozen food need to be avoided to reduce BPA levels.

Pancreatic impairment and Igf2 hypermethylation induced by developmental exposure to bisphenol A can be counteracted by maternal folate supplementation

Increasing evidence indicates that bisphenol A (BPA), a widely manufactured environmental pollutant, can induce changes in DNA methylation paatterns, which is a potential mechanism linking this environmental exposure to disease development. We investigated the influence of developmental exposure to BPA on pancreatic DNA methylation patterns and whether maternal folate supplementation can modify the epigenetic status and pancreatic impairment induced by BPA. Our results showed that maternal dietary folate supplementation in rats exposed to BPA counteracted the observed BPA-induced pancreatic impairments in the offspring, which included disrupted insulin secretion and glucose intolerance, and impaired morphology and ultrastructure of β cells. Moreover, these pancreatic dysfunctions were shown to be associated with low expression and DNA hypermethylation of insulin-like growth factor-2 (Igf2) in islets induced by exposure to BPA during the developmental period. Importantly, maternal dietary folate supplementation was demonstrated to negate this Igf2 DNA hypermethylation in the offspring, which was consistent with the upregulation of Igf2 expression. Overall, our results suggest that early developmental exposure to BPA alters the DNA methylation of Igf2, that these altered methylation patterns are associated with impaired β-cell function in the offspring and that these effects can be counteracted by maternal folate supplementation. Copyright © 2017 John Wiley & Sons, Ltd.

Low-Dose Bisphenol A Exposure: A Seemingly Instigating Carcinogenic Effect on Breast Cancer

Breast cancer is the fifth most common cause of cancer death in the world and the second most common fatal cancer in women. Epidemiological studies and clinical data have indicated that hormones, including estrogen, progesterone, and prolactin, play important roles in the initiation and progression of breast cancer. Bisphenol A (BPA) is one of the most commonly used and thoroughly studied endocrine disruptors. It can be released from consumer products and deposited in the environment, thus creating potential for human exposure through oral, inhaled, and dermal routes. Some recent reviews have summarized the known mechanisms of endocrine disruptions by BPA in human diseases, including obesity, reproductive disorders, and birth defects. However, large knowledge gaps still exist on the roles BPA may play in cancer initiation and development. Evidence from animal and in vitro studies has suggested an association between increased incidence of breast cancer and BPA exposure at doses below the safe reference doses that are the most environmentally relevant. Most current studies have paid little attention to the cancer-promoting properties of BPA at low doses. In this review, recent findings on the carcinogenic effects of low-dose BPA on breast cancer and discussed possible biologic mechanisms are summarized.

Adsorptive removal of bisphenol A (BPA) from aqueous solution: A review

Endocrine-disrupting compounds (EDCs) are an important class of emerging contaminants that have been detected (and are still being detected) in aquatic environments such as surface waters, groundwater, wastewater, runoff, and landfill leachates. Bisphenol A (BPA) is a known endocrine disruptor that is acutely toxic to the living organisms. BPA has been widely used in the manufacture of sunscreen lotions, nail polish, body wash/lotions, bar soaps, shampoo, conditioners, shaving creams, and face lotions/cleanser, besides its other industrial applications. In the present review, an overview of the recent research studies dealing with the BPA removal from water by adsorption method is presented. We have reviewed various conventional and non-conventional adsorbents which have been used for BPA removal from water. It is evident from the literature reviewed that modified adsorbents and composite materials have shown promising results for BPA removal from water. Literature has been extensively discussed in terms of adsorption capacities, fitted isotherm and kinetic models and thermodynamic aspects.

Enhanced visible-light-responsive photodegradation of bisphenol A by Cu, N-codoped titanate nanotubes prepared by microwave-assisted hydrothermal method

In this study, a rapid and effective microwave-assisted hydrothermal method was developed for the synthesis of Cu, N-codoped titanate nanotubes (Cu, N-TNTs) to enhance the photocatalytic degradation efficiency and rate of bisphenol A (BPA) under UV and visible light irradiations. The TNTs were first synthesized at 150°C for 3h under microwave heating conditions followed by the calcination at 450°C in the presence of 6wt% Cu ions and N₂/NH₃ to fabricate Cu, N-TNTs composites. The Cu, N-TNTs exhibited excellent photocatalytic activity toward BPA degradation under UV and visible light irradiations. The X-ray photoelectron spectra indicated that Cu species in Cu, N-TNTs were mainly in zerovalent form and could serve as the electron donors as well as shuttling species to accelerate the photodegradation of BPA. In addition, the nitrogen atoms were incorporated into the anatase lattices to increase the visible-light-responsive capability. The surface normalized reaction rate constants for BPA degradation were 4.3 and 1.5 times higher than those of Degussa P25 TiO₂ under UV and visible light irradiations, respectively. The electron spin resonance spectra showed that Cu, N-codoped TNTs prolonged the generation of oxygen-containing radicals for at least 5min, resulting in the significant enhancement of photodegradation efficiency and rate of BPA. Results obtained in this study open a new avenue by using simple and effective microwave-assisted hydrothermal method to fabricate low dimensional codoped TNTs which can be potentially applied in a wide variety of fields of purification, green chemistry and photocatalysis.

The association between bisphenol A exposure and type-2 diabetes: a world systematic review

The present study was conducted to systematically review, analyze, and interpret all the relevant evidence in the literature on the possible link between exposure to bisphenol A (BPA) and the risk of type-2 diabetes mellitus (T2DM). We developed a comprehensive search strategy and used it to search Web of Science, Scopus, PubMed, and Google Scholar up to March 31, 2016, producing 3108 hits, of which 13 original papers were included. Findings of these studies were quite controversial; few studies indicated a significant positive association between BPA exposure and T2DM, while some other failed to detect such a relationship. Overall, it can be suggested that chance is unlikely the plausible explanation for the observed association between BPA exposure and T2DM. This was mainly because even in the negative studies some clues could be found in favor of a statistically significant relationship between BPA and T2DM. Additionally, some of the studies had shortcomings in defining the exposure and outcome measures, which, if present, might have led to underestimating the relationship between BPA exposure and T2DM. The theoretical plausibility of such a relationship found earlier in animal studies also supports this point. However, more definitive answer requires the conduct of future longitudinal studies, in which the possible association between BPA exposure and T2DM is assessed over much longer periods of time with more temporally robust BPA measurements. In addition, it would be quite beneficial if future studies be conducted in areas where data is still lacking (e.g., South America, Australia/Oceania, and Europe). Graphical abstract ᅟ.

Selectivity Enhancement in Molecularly Imprinted Polymers for Binding of Bisphenol A

Bisphenol A (BPA) is an estrogen-mimicking chemical that can be selectively detected in water using a chemical sensor based on molecularly imprinted polymers (MIPs). However, the utility of BPA-MIPs in sensor applications is limited by the presence of non-specific binding sites. This study explored a dual approach to eliminating these sites: optimizing the molar ratio of the template (bisphenol A) to functional monomer (methacrylic acid) to cross-linker (ethylene glycol dimethacrylate), and esterifying the carboxylic acid residues outside of specific binding sites by treatment with diazomethane. The binding selectivity of treated MIPs and non-treated MIPs for BPA and several potential interferents was compared by capillary electrophoresis with ultraviolet detection. Baclofen, diclofenac and metformin were demonstrated to be good model interferents to test all MIPs for selective binding of BPA. Treated MIPs demonstrated a significant decrease in binding of the interferents while offering high selectivity toward BPA. These results demonstrate that conventional optimization of the molar ratio, together with advanced esterification of non-specific binding sites, effectively minimizes the residual binding of interferents with MIPs to facilitate BPA sensing.

The consumption of canned food and beverages and urinary Bisphenol A concentrations in NHANES 2003-2008

BACKGROUND

Exposure to Bisphenol A (BPA) is ubiquitous and includes dietary and environmental pathways. BPA is rapidly glucuronidated in the body, and both BPA and its conjugates can be readily measured in urine.

OBJECTIVES

To investigate the contribution of canned food and beverages, known sources of BPA contamination, to BPA biomarkers of exposure using dietary and urinary BPA concentration information in a representative sample of the U.S.

METHODS

We evaluated 7669 NHANES 2003-2008 participants 6 years and older with 24-h dietary recall information and urinary BPA concentrations available. Using linear regression models, we evaluated the associations between recent canned food and beverage consumption and urinary BPA concentrations, adjusting for potential confounders.

RESULTS

We found 9% of our participants consumed one canned food in the past 24h and 2% consumed two or more canned foods. The consumption of one canned food vs. none was associated with 24% (95% CI 1.11, 1.38) higher urinary BPA concentrations. The consumption of two or more canned foods vs. none was associated with 54% (95% CI 1.27, 1.88) higher urinary BPA concentrations. The consumption of one or more of some specific types of canned foods vs. none were associated with higher urinary BPA concentrations: 41% (95% CI 1.23, 1.63) higher BPA for vegetable and fruit, 70% (95% CI 1.18, 2.44) higher for canned pasta, and 229% (95% CI 1.22, 4.30) higher for canned soup. Canned beverages were not associated with urinary BPA concentrations.

CONCLUSIONS

Canned food, including some specific types such as canned vegetable and fruit, canned pasta, and canned soup were associated with higher levels of urinary BPA concentrations.

Molecular Dynamics Simulations of the Permeation of Bisphenol A and Pore Formation in a Lipid Membrane

Bisphenol A (BPA) is particularly considered as one of the most suspicious endocrine disruptors. Exposure to BPA may bring about possible human toxicities, such as cancerous tumors, birth defects and neoteny. One of the key issues to understand its toxicities is how BPA enters cells. In this paper, we perform molecular dynamics simulations to explore the interactions between BPA and a phospholipid membrane (dipalmitoylphosphatidylcholine, DPPC bilayer). The simulation results show that BPA can easily enter the membrane from the aqueous phase. With the increasing concentrations of BPA in the membrane, BPA tends to aggregate and form into cluster. Meanwhile, several DPPC lipids are pulled out from each leaflet and adsorbed on the cluster surface, leading to pore formation. Detailed observations indicate that the lipid extraction results mainly from the dispersion interactions between BPA cluster and lipid tails, as well as weak electrostatic attractions between lipid headgroups and the two hydroxyl groups on BPA. The lipid extraction and pore formation may cause cell membrane damage and are of great importance to uncover BPA’s cytotoxicity.

Mechanical Properties of Composites Used in High-Voltage Applications

Materials used in high voltage applications have to meet a lot of regulations for their safety and functional usage during their lifetime. For high voltage applications the electrical properties are the most relevant designing criteria. However, the mechanical properties of such materials have rarely been considered for application dimensioning over the last decades. This article gives an overview of composite materials used in high voltage applications and some basic mechanical and thermo-mechanical characterization methods of such materials, including a discussion of influences on practically used epoxy based thermosets.

A review on bisphenol A occurrences, health effects and treatment process via membrane technology for drinking water

Massive utilization of bisphenol A (BPA) in the industrial production of polycarbonate plastics has led to the occurrence of this compound (at μg/L to ng/L level) in the water treatment plant. Nowadays, the presence of BPA in drinking water sources is a major concern among society because BPA is one of the endocrine disruption compounds (EDCs) that can cause hazard to human health even at extremely low concentration level. Parallel to these issues, membrane technology has emerged as the most feasible treatment process to eliminate this recalcitrant contaminant via physical separation mechanism. This paper reviews the occurrences and effects of BPA toward living organisms as well as the application of membrane technology for their removal in water treatment plant. The potential applications of using polymeric membranes for BPA removal are also discussed. Literature revealed that modifying membrane surface using blending approach is the simple yet effective method to improve membrane properties with respect to BPA removal without compromising water permeability. The regeneration process helps in maintaining the performances of membrane at desired level. The application of large-scale membrane process in treatment plant shows the feasibility of the technology for removing BPA and possible future prospect in water treatment process.

Paper-based analytical devices for environmental analysis

The field of paper-based microfluidics has experienced rapid growth over the past decade. Microfluidic paper-based analytical devices (μPADs), originally developed for point-of-care medical diagnostics in resource-limited settings, are now being applied in new areas, such as environmental analyses. Low-cost paper sensors show great promise for on-site environmental analysis; the theme of ongoing research complements existing instrumental techniques by providing high spatial and temporal resolution for environmental monitoring. This review highlights recent applications of μPADs for environmental analysis along with technical advances that may enable μPADs to be more widely implemented in field testing.

Bisphenol A in Urine of Chinese Young Adults: Concentrations and Sources of Exposure

Bisphenol A (BPA) is an endocrine disrupting environmental chemical. Urinary concentrations of BPA were measured in samples collected nationwide from Chinese young adults. The geometric mean urinary concentration of BPA in Chinese young adults was 2.23 ng/mL. The estimated daily exposure dose for BPA was 64.8 ng/kg bw/day. Contributions of various BPA sources to exposure in Chinese young adults were estimated. Dietary intake was the primary exposure pathway. The contribution of dietary intake, indoor dust, paper products and personal care products to BPA intake was 72.5 %, 0.74 %, 0.98 %, 0.22 % of the total exposure dose, respectively. This is the first study on the occurrence of BPA in young adults from most provinces and autonomous regions of China. The results can be used to establish a database for BPA exposure assessment for Chinese general population.

Bisphenol A and other bisphenol analogues including BPS and BPF in surface water samples from Japan, China, Korea and India

Concentrations of eight bisphenol analogues (BPs) including BPA, BPS, and BPF were determined in surface waters collected from select rivers in Japan, Korea, China, and India. BPA was found at a concentration in the range of several tens to several hundreds of nanograms per liter in most of the rivers surveyed and some of the highest concentrations (54-1950 ng/L) were found in rivers in Chennai, India. Concentrations of BPF were one to two orders of magnitude higher than those of BPA in river and sea waters collected from Japan, Korea and China, which suggested that BPF is a major contaminant in surface waters in several Southeast Asian countries. BPF concentrations as high as 2850 ng/L were found in the Tamagawa River in Japan. The flux of BPs through riverine discharges into Tokyo Bay was calculated to be approximately 5.5 t per year. Based on the flux estimates and the mass of BPF found in water column and sediment in Tokyo Bay, it was found that BPF degrades faster than BPA in the environment. Elevated concentrations of BPF found in surface waters suggest the need for further studies to determine the fate and toxicity of this compound.

Effects of bisphenol A, an environmental endocrine disruptor, on the endogenous hormones of plants

Bisphenol A (BPA) is a ubiquitous endocrine-disrupting chemical in the environment that exerts potential harm to plants. Phytohormones play important roles both in regulating multiple aspects of plant growth and in plants' responses to environmental stresses. But how BPA affects plant growth by regulating endogenous hormones remains poorly understood. Here, we found that treatment with 1.5 mg L(-1) BPA improved the growth of soybean seedlings, companied by increases in the contents of indole-3-acetic acid (IAA) and zeatin (ZT), and decreases in the ratios of abscisic acid (ABA)/IAA, ABA/gibberellic acid (GA), ABA/ZT, ethylene (ETH)/GA, ETH/IAA, and ETH/ZT. Treatment with higher concentrations of BPA (from 3 to 96 mg L(-1)) inhibited the growth of soybean seedlings, meanwhile, decreased the contents of IAA, GA, ZT, and ETH, and increased the content of ABA and the ratios of ABA/IAA, ABA/GA, ABA/ZT, ETH/GA, ETH/IAA, and ETH/ZT. The increases in the ratios of growth and stress hormones were correlated with the increase in the BPA content of the roots. Thus, BPA could affect plant growth through changing the levels of single endogenous hormone and the ratios of growth and stress hormones in the roots because of BPA absorption by the roots.

Identification of Putative Genes Involved in Bisphenol A Degradation Using Differential Protein Abundance Analysis of Sphingobium sp. BiD32

Discharge of the endocrine disrupting compound bisphenol A (BPA) with wastewater treatment plant (WWTP) effluents into surface waters results in deleterious effects on aquatic life. Sphingobium sp. BiD32 was previously isolated from activated sludge based on its ability to degrade BPA. This study investigated BPA metabolism by Sphingobium sp. BiD32 using label-free quantitative proteomics. The genome of Sphingobium sp. BiD32 was sequenced to provide a species-specific platform for optimal protein identification. The bacterial proteomes of Sphingobium sp. BiD32 in the presence and absence of BPA were identified and quantified. A total of 2155 proteins were identified; 1174 of these proteins were quantified, and 184 of these proteins had a statistically significant change in abundance in response to the presence/absence of BPA (p ≤ 0.05). Proteins encoded by genes previously identified to be responsible for protocatechuate degradation were upregulated in the presence of BPA. The analysis of the metabolites from BPA degradation by Sphingobium sp. BiD32 detected a hydroxylated metabolite. A novel p-hydroxybenzoate hydroxylase enzyme detected by proteomics was implicated in the metabolic pathway associated with the detected metabolite. This enzyme is hypothesized to be involved in BPA degradation by Sphingobium sp. BiD32, and may serve as a future genetic marker for BPA degradation.

A review of the carcinogenic potential of bisphenol A

The estrogenic properties of bisphenol A (BPA), a ubiquitous synthetic monomer that can leach into the food and water supply, have prompted considerable research into exposure-associated health risks in humans. Endocrine-disrupting properties of BPA suggest it may impact developmental plasticity during early life, predisposing individuals to disease at doses below the oral reference dose (RfD) established by the Environmental Protection Agency in 1982. Herein, we review the current in vivo literature evaluating the carcinogenic properties of BPA. We conclude that there is substantial evidence from rodent studies indicating that early-life BPA exposures below the RfD lead to increased susceptibility to mammary and prostate cancer. Based on the definitions of "carcinogen" put forth by the International Agency for Research on Cancer and the National Toxicology Program, we propose that BPA may be reasonably anticipated to be a human carcinogen in the breast and prostate due to its tumor promoting properties.

High Levels of Bisphenol A and Bisphenol S in Brazilian Thermal Paper Receipts and Estimation of Daily Exposure

Bisphenol A (BPA) is an endocrine and metabolic disruptor commonly employed as a color developer in thermal papers. Consequently, BPA derived from thermal papers has been considered an important source of exposure for humans, since this chemical may migrate from paper to skin upon contact. Further, due to recent restrictions on BPA use in some countries, it has been replaced by a new analogue, bisphenol S (BPS). The aim of the present study was to determine levels of BPA and BPS in 190 different thermal receipts, randomly collected from different locations in São Paulo State, Brazil, including receipts from supermarkets, general and fast-food restaurants, gas stations, bus and airplane tickets, and credit card and bank accounts. BPA and/or BPS were detected in 98% of samples at concentrations ranging from below the quantification limit to 4.3% (mg/100 mg paper). The obtained values were higher than amounts previously reported in other countries. The estimated daily intake through dermal absorption from handling of thermal receipt papers was estimated on the basis of concentrations and frequencies of handling of papers by humans in both the general population and occupationally exposed individuals. Fifth percentile, median, and 95th percentile daily intakes by the general population were 0.44, 1.42, and 2 μg/d, respectively, whereas the corresponding values for occupationally exposed population are 21.8, 71 and 101 μg/d. The potential adverse consequences of elevated occupational exposure are currently being examined.

Global Assessment of Bisphenol A in the Environment: Review and Analysis of Its Occurrence and Bioaccumulation

Because bisphenol A (BPA) is a high production volume chemical, we examined over 500 peer-reviewed studies to understand its global distribution in effluent discharges, surface waters, sewage sludge, biosolids, sediments, soils, air, wildlife, and humans. Bisphenol A was largely reported from urban ecosystems in Asia, Europe, and North America; unfortunately, information was lacking from large geographic areas, megacities, and developing countries. When sufficient data were available, probabilistic hazard assessments were performed to understand global environmental quality concerns. Exceedances of Canadian Predicted No Effect Concentrations for aquatic life were >50% for effluents in Asia, Europe, and North America but as high as 80% for surface water reports from Asia. Similarly, maximum concentrations of BPA in sediments from Asia were higher than Europe. Concentrations of BPA in wildlife, mostly for fish, ranged from 0.2 to 13 000 ng/g. We observed 60% and 40% exceedences of median levels by the US Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey in Europe and Asia, respectively. These findings highlight the utility of coordinating global sensing of environmental contaminants efforts through integration of environmental monitoring and specimen banking to identify regions for implementation of more robust environmental assessment and management programs.

Ubiquitous occurrence of chlorinated byproducts of bisphenol A and nonylphenol in bleached food contacting papers and their implications for human exposure

The occurrence of bisphenol A (BPA), nonylphenol (NP), and their six chlorinated byproducts were investigated in 74 food contacting papers (FCPs) from China, the U.S.A., Japan, and Europe using a sensitive dansylation LC-MS/MS method. BPA (<LOQ-83 ng/g) and NP (<LOQ-5.4 ng/g) were widely detected in FCPs, while the six chlorinated byproducts were detected in less than half of the samples. The concentrations of chlorinated BPAs and chlorinated NPs in FCPs were significantly correlated with the concentrations of BPA and NP, respectively, and their concentrations mainly depended on bleaching processes in paper production. The mean concentrations of monochloro-BPA (MCBPA), dichloro-BPA (DCBPA), trichloro-BPA (TCBPA), tetrachloro-BPA (TeCBPA), monochloro-NP (MCNP), and dichloro-NP (DCNP) in bleached FCPs were 0.019 ± 0.025, 0.0033 ± 0.0059, 0.0030 ± 0.0045, 0.0081 ± 0.019, 0.23 ± 0.46, and 0.066 ± 0.11 ng/g, respectively, much higher than those (0.0021 ± 0.0020 ng/g for MCBPA, 0.00068 ± 0.00076 ng/g for DCBPA, <LOQ for TCBPA and TeCBPA, 0.006 ± 0.003 ng/g for MCNP, and <LOQ for DCNP) in unbleached FCPs. Furthermore, it was shown that BPA, NP, and some of their chlorinated byproducts could migrate from coffee filters into coffee solution with migration rates of 71 ± 10% for BPA, 2.4 ± 0.33% for NP, 47 ± 1.4% for MCBPA, and 0.35 ± 0.11% for MCNP. This is the first report on the occurrence of chlorinated derivatives of BPA and NP in FCPs and their migration, which provides important information to comprehensively understand human exposure to BPA, NP, and their chlorinated derivatives.