Article

Leaching of bisphenol A (BPA) from polycarbonate plastic to water containing amino acids and its degradation by radical oxygen species

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Abstract

In this study, (1) the change in the concentration of bisphenol A (BPA) leached from polycarbonate plastic (PCP) tube to water samples containing phosphate, sodium barbital, glycine, methionine or albumin at 37 degrees C as a function of time, and (2) the degradation rate of BPA leached from PCP tube to amino acid solutions in the presence of radical oxygen species (ROS) were investigated. The BPA leaching velocity (BPA-LV) from PCP tube to 50 mM glycine at pH 6 or 7 was twice that to control water, and the leaching was enhanced above pH 8. At pH 11, BPA-LV was significantly higher in 50 mM glycine and methionine solutions than in 50 mM NaOH. These results indicate that basic pH and amino acids contained in water could accelerate BPA leaching. The BPA-LV in phosphate buffer was different from the BPA-LVs in other buffers (barbital and glycine) at the same pH. BPA leached to the glycine or methionine solutions at pH 11 was degraded time dependently in a similar manner as the control water in the presence of ROS. The degradation of leached BPA was inhibited in the glycine solution, but was accelerated in the methionine solution. However, degradation of BPA added to freshly prepared methionine was inhibited in a similar manner to BPA in glycine. BPA degradation could be influenced by some kinds of amino acids, but glycine and methionine might be involved in BPA degradation in different ways.

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... Matrices in which BPA was analyzed were canned food and beverages, milk, honey, polycarbonate plastics, paper, urine, human breast milk, blood, blood serum, sewage sludge, sea and river water, sediment, and drinking water. [12][13][14][15][16][17][18][19][20][21][22][23] Reversed-phase liquid chromatography was the most frequently used separation technique with acetonitrile/water or methanol/water mobile phases. UV absorption was a widely used detection technique [6,12,14] followed by more sensitive and selective fluorescence detection, [18,22] electrochemical detection, [13,19] and tandem mass spectrometry. ...
... [12][13][14][15][16][17][18][19][20][21][22][23] Reversed-phase liquid chromatography was the most frequently used separation technique with acetonitrile/water or methanol/water mobile phases. UV absorption was a widely used detection technique [6,12,14] followed by more sensitive and selective fluorescence detection, [18,22] electrochemical detection, [13,19] and tandem mass spectrometry. [20,21] Due to the variety of samples, a broad range of sample preparation techniques was used. ...
... [21,22] Many analytical procedures included solid-phase extraction on nonpolar, ion-exchange or mixed-mode stationary phases depending whether the purpose was concentration of analyte or removal of the interferences. [12][13][14][15][16][17]19,21,22] In some cases, samples were derivatized to improve the sensitivity: for example samples of ready-made meals with pyridine-3sulphonyl chloride to enable more sensitive positive ionization in tandem mass spectrometry (MS/MS) detection. [21] Benzophenone (BFN), another pseudoestrogenic compound frequently used as a UV screen in various products, can be an ingredient in UV-curing thermochromic inks as well. ...
Article
The endocrine disruptors bisphenol A (BPA) and benzophenone (BFN) could be important ingredients in thermochromic printing inks in significant amounts. Due to patent protection and use of the inks, manufacturers are not obliged to state their precise chemical composition. These substances in increasingly used thermochromic printing inks present a hazard for human health and environment in the case of inappropriate application and waste disposal. In this work we enabled identification of the inks that contain these hazardous substances by developing a new method for the analysis of BPA and BFN in thermochromic printing inks. The method is based on the reversed-phase liquid chromatography (LC) with UV detection at 226 and 254 nm. Ultrasound-assisted sample extraction in methanol was proven to be the most suitable and effective among several other solvents. The method was completely validated with satisfactory results. The specificity of the method was proven by the additional LC–tandem mass spectrometry analysis. A representative group of 15 ink samples from various manufacturers, curing and printing modes was analyzed. BPA was found in three samples with mass fractions of about 2% while BFN was found in two samples with mass fractions of 0.34 and 0.66%.
... The leaching of BPA from materials can occur [7], leading to its release into the environment, which is considered to be the source of contamination [8]. Due to its constant release and leakage from the plastic products, this hazardous molecule has "pseudo-persistent" characteristics in spite of being biodegradable in the environment [3,6]. ...
... The accumulation of plastic waste in the marine environment is worrying as studies have shown that BPA from plastic leaks faster [7,14], while its bacterial degradation is much slower [15] in marine than in freshwater systems. ...
Article
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Over the last decade, bisphenol A (BPA) has become a chemical of concern in the marine environment. There is little data on BPA levels in the eastern Adriatic Sea, Croatian waters. This study provides concentrations of BPA in marine sediments and suspended matter sampled from the Kaštela Bay (the central part of the Adriatic Sea) for two years. The results obtained show that BPA in sediment samples ranged from 1.05 to 46.31 µg kg-1, while they were higher in the suspended matter, ranging from 1.84 to 81.39 µg kg-1. To demonstrate a possible correlation between BPA concentrations and other parameters in sediment and suspended matter, the granulometric composition and organic matter content were determined. There was no correlation between BPA and investigated sediment characteristics. To assess the possible effects of BPA on marine biota, its possible estrogenic effect was also investigated by calculating estradiol equivalent concentration (EEQ, µg kg-1), the maximum value of which, in this study, was 0.0181 µg kg-1 in the sediment samples and 0.0317 µg kg-1 in suspended matter samples. Based on the presented results, it is unlikely that BPA could cause significant endocrine disruption to marine life in the study area.
... Dropping of pH also initiates leaching of BPA from dental resin composite and adhesives. [28][29][30] For Modern dental filling material, average amount for one filling (approximately 0.25 g) contains less than 0.5 µg of BPA comparing to traditional filling material which contains 5 µg BPA. After being used for 1 year, accumulated BPA release was still less than EFSA and US EPA standard for one day. ...
Article
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Bisphenol-A(BPA) and Dioxins pose a serious threat to human health. Estrogenicity is the main effect to human being caused by BPA overdose. In addition, Dioxins are ones of the most hazardous chemicals to the systemic health. This review gathered the detail information of these two toxic products in terms of chemical formulas and hazard to human general and oral health. Orthodontic aspect of these two chemicals is intriguing and included. While BPA releases from orthodontic material, Dioxins may cause dental defect especially permanent molar and incisor [Molar-incisor hypomineralization (MIH)]. Although the amount of BPA released from orthodontic material is well below the standard, recommendations for orthodontist of how to minimize this BPA release were given. The suggested role of orthodontist to manage the Dioxins toxicity to the dental health in the community was also versed.
... BPA (Fig. S1), an endocrine disrupting compound (EDCs), is widely used for making plastic products such as water bottles. Under acidic or basic conditions, the BPA is easily leached out from BPA-based products when its ester bonds linkage are hydrolyzed [1]. Due to their wide use, human exposure to the BPA is unavoidable. ...
... Studies have indicated that food and drinks stored in such containers can contain trace amount of BPA, a synthetic chemical that interferes with the body's natural hormonal messaging system. The same studies found that repeated re-use of such bottles, which get dinged up through normal wear and tear and while being washed, increases the chance that chemicals will leak out of the tiny cracks and crevices that develop over time (Groff 2010; Huang et al. 2011; Lang et al. 2008; Lee et al. 2008; Oehlmann et al. 2008; Rubin et al. 2001; Sajiki 2001; Sajiki and Yonekubo 2004; Vandenberg et al. 2007; Woodruff et al. 2010). Other studies also indicated that a toxic chemical, phthalates, also leaches from plastic material containers which affects living organisms (Al-Saleh et al. 2011; Chen et al. 2008; Heudorf et al. 2007; Martino-Andrade and Chahoud 2010; Montuori et al. 2008; Sajiki and Yonekubo 2003; Schettler 2006; Wagner and Oehlmann 2009; 2011). ...
Article
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ABSTRACT In many developing countries such as Ethiopia, most people show little regard for the environment resulting people to reuse the non biodegradable plastic water bottles and bags. Poor mechanism cause environment worse and encircled living organisms at risk. Reusing plastic materials with poor cleaning system result leaching of chemical pollutants, such as bisphenol A, phthalates and antimony that causes serious toxicolog humans and reduce the aesthetic values of the environment. Annually, over 23 million plastic water bottles and bags are consumed in Tigray. Most plastic materials are reused and end up in the solid waste stream. Now, plastic materials const challenge to solid waste management in Mekelle, the capital of Tigray and home to more than 215 thousand people. Poor handling, reusing and disposal of plastic waste, which are major causes of environmental pollution, becomes grounds for pathogenic organisms, the spread of infectious diseases and loss of environmental aesthetics. This study examines the adverse impacts of reusing plastic water bottles and bags on people and the environment; and initiates the municipalities at a regional and national level plastic materials in line with their sustainable waste management’s. Creating awareness through education among communities coupled with improving acc waste management will help to achieve sound public and environmental health in Mekelle, Tigray.
... La contamination à partir des aliments est faite soit par migration des polymères dans l'aliment, soit par libération du BPA par l'hydrolyse du polymère, en particulier au cours du chauffage, comme cela peut se produire pour les biberons en polycarbonate par exemple. Cette migration est d'autant plus importante que le polycarbonate a été utilisé à de nombreuses reprises [11, 12] ou qu'il est au contact de solutions alcalines [13]. D'autres facteurs interviennent : l'exposition aux UV, le passage au lavevaisselle , le nettoyage avec des détergents puissants) [10]. ...
Article
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Résumé. Le bisphénol A est un composé chimique issu de la réaction entre le phénol et l'acétone. C'est un monomère chimique utilisé dans la production du polycarbonate et des résines époxy-phénoliques lesquels sont utilisés dans plusieurs domaines (alimentation, dentis-terie, papeterie, dispositifs médicaux, etc.). La principale source d'exposition de la population générale au bisphénol A serait alimentaire par passage dans l'aliment ou la boisson à partir des polymères en plastiques et résines époxy, utilisés pour les emballer. Le bisphénol A est un perturbateur endocrinien avec une activité oestrogénique. Il entraîne une diminution de la production du sperme, augmente le volume de la prostate et altère le développement de la morphologie vaginale et du cycle oestrogénique ; d'autres études ont suggéré l'effet sur la thyroïde, la prostate, le système cardiovasculaire, il pourrait induire le diabète de type 2, ainsi que des anomalies enzymatiques du foie. Les effets sur la santé sont connus actuellement à la suite d'études chez l'animal. Cependant, les études chez l'homme ne sont pas plau-sibles et ne confirment pas les effets décrits sur la santé ce qui nécessite d'autres études plus poussées. Abstract. Bisphenol A is a chemical compound from the reaction between the phenol and ace-tone. It is a chemical monomer used in the production of polycarbonate and epoxy-phenolic resins which are used in many areas (food, dentistry, stationery, medical devices. . .). Food could be the main source of population exposure to bisphenol A that would pass through food or drink from the polymers in plastic and epoxy resins used for packing. BPA is an endocrine disruptor with estrogenic activity. It causes a decrease in sperm production, increases prostate volume and alters the development of the morphology and vaginal estrogenic cycle, other studies have suggested the effect on the thyroid, prostate, cardiovascular system, it may induce type 2 diabetes and liver enzyme abnormalities. The health effects are known at present by ani-mal studies. However, studies in humans are not plausibles and do not confirm the described effects on health which requires further studies.
... Being present in many household products such as baby bottles, plastic containers, inner linings of food cans, and receipt paper, BPA and its potential long-term consequences on organisms have been increasingly monitored and documented by clinical labs. [2,4] Through analyzing concentration levels and the corresponding health effects of BPA in consumer goods, a more comprehensible profile of the compound's potential harmful effects will be achieved. Based on the levels found in BPAcontaining materials, federal regulations can be implemented to limit the amount of BPA in such products. ...
Article
A simple and efficient method for determination of Bisphenol A (BPA), an endocrine disrupting chemical (EDC), is developed without the requirement of derivatization. Due to the prevalence of exposure of BPA-containing products to the general public, high-quality testing and monitoring methods are essential. BPA was separated and quantified under reverse-phase conditions using a high-performance liquid chromatography/ultraviolet absorption (HPLC-UV) detection method. A silica hydride-based C8 column along with an effective gradient protocol yielded well-resolved peaks that allowed for the direct analyses of BPA in receipt paper and carbon copies of lab notebooks. Excellent linear correlation was observed (R2 = 0.9936) in the calibration curve obtained from the HPLC-UV analyses.
... Introduction to high temperatures, acidic or basic solutions, and physical damage can lead to the hydrolysis of plastic polymers into the estrogenic monomer. Breakdown of BPA has been reported in several products including baby bottles, water bottles, polyvinyl chloride (PVC) tubing, and plastic containers (Carwile et al., 2009;Lopez-Cervantes & Paseiro-Losada, 2003;Mountfort, Kelly, Jickells, & Castle, 1997;Nerin, Fernandez, Domeno, & Salafranca, 2003;Sajiki & Yonekubo, 2004). BPA can enter our ecosystems when consumer products are disposed into wastewater systems and landfills. ...
Article
The ubiquitous monomer, bisphenol A (BPA), is an endocrine active compound used in the production of polycarbonate plastics and epoxy resin. Environmental biomonitoring and epidemiology studies report continuous exposure in humans that are associated with different adverse health outcomes. The overall goal of this work was to characterize BPA concentrations, toxicokinetic and toxicodynamic profiles that influence tissue-specific BPA biotransformation via xenobiotic metabolizing enzymes (XME), and BPA dependent changes in biotransformation using healthy 1st-2nd trimester clinical specimens obtained from a fetal biobank. First, we reported a wide range of BPA concentrations in N=50 fetal liver specimens (total BPA range: below limit of quantification - 96.8 ng/g). Both concentrations and metabolic profiles varied across age with significant reduction in BPA-specific XME gene expression of UGT2B15, SULT1A1, and STS in fetal versus adult livers. Next, we examined matched fetal liver, kidney, and placenta in N=12 subjects and observed significant tissue-dependent differences in BPA concentrations, XME expression profiles, and global DNA methylation. Fetal livers exhibited higher BPA concentrations compared to matched tissues; however, XME expression profiles suggest an increased likelihood of BPA-glucuronide deconjugation and BPA-sulfate conjugation across the fetal compartments. With organ-specific differences in the epigenome, only placental global methylation measurements were associated with BPA. Finally, we investigated BPA???s role in pathway specific biological outcomes and regulation in fetal liver. In particular, we identified 14 different XME candidate genes that were down regulated with higher BPA concentrations. In summary, results suggest that the 1st-2nd trimester human fetus is exposed to a considerable amount of BPA in utero, especially of the active free BPA form. XME expression profiles reveal an altered capacity for BPA biotransformation in the fetus compared to adults, with distinct metabolic profiles across different tissues. Interestingly, higher BPA concentrations in fetal liver were associated with reduced expression of novel XME candidate genes mediated by epigenetic mechanisms. These findings indicate that environmentally relevant concentrations of BPA, even across a short window of development, result in detectable changes in the host???s toxicological defense system.
... BPA is used in the manufacturing of many products, including polycarbonate and epoxy plastic food packaging material, and it has been shown that BPA leaches from containers into foodstuff (Sajiki and Yonekubo 2004;Vandenberg et al. 2007). Geens et al. (2012) estimated a daily human exposure level of 0:1-5 lg=kg bw=d from dietary and nondietary sources. ...
Article
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Background: Bisphenol A (BPA) is an endocrine-disrupting chemical that may contribute to development of obesity and metabolic disorders. Humans are constantly exposed to low concentrations of BPA, and studies support that the developmental period is particularly sensitive. Objectives: The aim was to investigate the effects of low-dose developmental BPA exposure on metabolic parameters in male and female Fischer 344 (F344) rat offspring. Methods: Pregnant F344 rats were exposed to BPA via their drinking water, corresponding to 0.5 μg/kg BW/d (BPA0.5; n =21) or 50 μg/kg BW/d (BPA50; n =16), from gestational day (GD) 3.5 until postnatal day (PND) 22, and controls were given vehicle ( n =26). Body weight (BW), adipose tissue, liver (weight, histology, and gene expression), heart weight, and lipid profile were investigated in the 5-wk-old offspring. Results: Males and females exhibited differential susceptibility to the different doses of BPA. Developmental BPA exposure increased plasma triglyceride levels (0.81±0.10 mmol/L compared with 0.57±0.03 mmol/L, females BPA50 p =0.04; 0.81±0.05 mmol/L compared with 0.61±0.04 mmol/L, males BPA0.5 p =0.005) in F344 rat offspring compared with controls. BPA exposure also increased adipocyte cell density by 122% in inguinal white adipose tissue (iWAT) of female offspring exposed to BPA0.5 compared with controls (68.2±4.4 number of adipocytes/HPF compared with 55.9±1.5 number of adipocytes/HPF; p =0.03) and by 123% in BPA0.5 females compared with BPA50 animals (68.2±4.4 number of adipocytes/high power field (HPF) compared with 55.3±2.9 number of adipocytes/HPF; p =0.04). In iWAT of male offspring, adipocyte cell density was increased by 129% in BPA50-exposed animals compared with BPA0.5-exposed animals (69.9±5.1 number of adipocytes/HPF compared with 54.0±3.4 number of adipocytes/HPF; p =0.03). Furthermore, the expression of genes involved in lipid and adipocyte homeostasis was significantly different between exposed animals and controls depending on the tissue, dose, and sex. Conclusions: Developmental exposure to 0.5 μg/kg BW/d of BPA, which is 8-10 times lower than the current preliminary EFSA (European Food Safety Authority) tolerable daily intake (TDI) of 4 μg/kg BW/d and is within the range of environmentally relevant levels, was associated with sex-specific differences in the expression of genes in adipose tissue plasma triglyceride levels in males and adipocyte cell density in females when F344 rat offspring of dams exposed to BPA at 0.5 μg/kg BW/d were compared with the offspring of unexposed controls. https://doi.org/10.1289/EHP505.
... BPA is used in the manufacturing of many products, including polycarbonate and epoxy plastic food packaging material, and it has been shown that BPA leaches from containers into foodstuff (Sajiki and Yonekubo 2004;Vandenberg et al. 2007). Geens et al. (2012) estimated a daily human exposure level of 0:1-5 lg=kg bw=d from dietary and nondietary sources. ...
Article
Full-text available
Background: Bisphenol A (BPA) is a component of polycarbonate plastics to which humans are regularly exposed at low levels, and an endocrine disruptor with effects on several hormonal systems. Bone is a sensitive hormone target tissue, and we have recently shown that in utero and lactational exposure to 25µg BPA/kg BW/day alters femoral geometry in rat offspring. Objective: To investigate bone effects in rat offspring after developmental exposure to a BPA dose in the range of human daily exposure (0.1-1.5µg/kg BW/day) as well as a dose to corroborate previous findings. Methods: Pregnant Fischer 344 rats were exposed to BPA via drinking water corresponding to 0.5µg/kg BW/day: [0.5], (n=21) or 50µg/kg BW/day: [50], (n = 16) from gestational day 3.5 until postnatal day 22, while controls were given only vehicle (n = 25). The offspring was sacrificed at 5 weeks of age. Bone effects were analyzed using peripheral quantitative computed tomography (pQCT), the 3-point bending test, plasma markers of bone turnover, and gene expression in cortical bone and bone marrow. Results: Compared to controls, male offspring developmentally exposed to BPA had shorter femurs. pQCT analysis revealed effects in the [0.5] group, but not in the [50] group; BPA reduced both trabecular area (-3.9%, p < 0.01) and total cross sectional area (-4.1%, p < 0.01) of femurs in the [0.5] group, whereas no effects were seen on bone density. Conversely, bone length and size were not affected in female offspring. However, the procollagen type I N-terminal propeptide (P1NP), a peptide formed during type 1 collagen synthesis, was increased in plasma (42%: p < 0.01) in female offspring exposed to [0.5] of BPA, although collagen gene expression was not increased in bone. The biomechanical properties of the bones were not altered in either sex. Bone marrow mRNA expression was only affected in male offspring. Conclusions: Developmental low-dose exposure to BPA resulted in sex-specific bone effects in rat offspring. A dose approximately eight times lower than the current temporary EFSA human tolerable daily intake of 4µg/kg BW/day, reduced bone length and size in male rat offspring. Long-term studies are needed to clarify whether the increased plasma levels of P1NP in female offspring reflect development of fibrosis.
... However, it is also important to recognize the significance of the reported contamination of oceans [110][111][112] and sediments. 11,67,113 The presence of polycarbonate in oceans is of special concern because leaching of 1a from polycarbonate occurs more rapidly in sea than in fresh waters, 74,114 1a oxidation by radical oxygen species is slower in seawater than in control water, 71 and marine bacteria strains have been found to degrade 1a much more slowly than freshwater strains. 107,115 Furthermore, 1a has been detected in marine organisms including phytoplankton, zooplankton, mussels, herring, flounder, and cod, and bioamplification between phytoplankton and zooplankton has been documented. ...
Article
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Designing technologies that mitigate the low-dose adverse effects of exposures to large-volume everyday-everywhere chemicals such as bisphenol A (BPA, 1a ) requires an understanding of the scope of the exposures and...
... In addition to WWTP effluent and rainfall runoff, microplastics may be potential sources for BPs in surface water due to the release of monomers during the aging process. Numerous studies have shown that BPA will be available for leaching from microplastics in seawater and surface water (Notardonato et al. 2019;Sajiki and Yonekubo 2004;Xu et al., 2020) Meanwhile, some available studies have investigated the presence of microplastics in surface water in China, including Yongjiang River, Pearl River, Hanjiang River, and Yangtze River Lin et al. 2018;Wang et al. 2017), with the abundance ranges of 379-8920 items/m 3 . Thus, microplastics may contribute to BPs in surface water, although more knowledge is needed to verify the hypothesis. ...
Article
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Bisphenol analogues (BPs) including bisphenol a (BPA) have been broadly utilized as industrial feedstocks and unavoidably discharged into water bodies. However, there is little published data on the occurrence, distribution, and environmental risks of other BPs in surface water. In this study, ten BPs besides BPA were analyzed in surface water from the Pearl River, South China. Among these detected BPs, BPA, bisphenol F (BPF), bisphenol AF (BPAF), and bisphenol S (BPS) were the most frequently detected compounds. The median concentrations of the measured BPs were ranked in the order of BPA (34.9 ng/L) > BPS (24.8 ng/L) > BPAF (10.1 ng/L) > bisphenol F (BPF) (9.0 ng/L) > bisphenol B (BPB) (7.6 ng/L) > bisphenol C (BPC) (1.2 ng/L). Among them, BPA and BPS were predominant BPs, contributing 68% of the total ten BPs in surface water of the Pearl River. These results demonstrated that BPA and BPS were the most extensively utilized and manufactured BPs in this region. The source analysis of BPs suggested that the BPs may be originated from domestic wastewater, wastewater treatment plant (WWTP) effluent, and the leaching of microplastic in surface water of the Pearl River. The calculated BP-derived estrogenic activity exhibited low to medium risks in surface water, but their combined estrogenic effects with other endocrine disrupting compounds should not be ignored.
... Because of its cross-linking properties in the manufacture of polycarbonate materials and epoxy resins, this compound has been widely used in the production of plastics since 1957 [5,6]. Therefore, leaching of BPA from polycarbonate plastics, baby bottles, dental sealants, epoxy resin linings for food and beverage containers, water pipes, and thermal papers makes it a ubiquitous contaminant of the environment [7,8]. It can bioaccumulate both in ground water, wastewater, and air leading to continual exposure of humans and animals, whereas for most species food is the major route of exposure [9]. ...
Chapter
Nowadays, many different chemicals exerting negative effects on both human and animal health are widely present in the environment. Compounds that interfere in the action of endocrine system due to their structural similarities to the real hormones called endocrine disrupting chemicals have received much attention because they are suspected to affect reproduction, development, metabolism of living organisms and even induce cancer. Moreover, the endocrine-related disorders are often passed down to the next generations and alter their disease susceptibility. This group of substances includes both naturally occurring chemicals (e.g., phytoestrogen—coumestrol) and synthetic compounds used in industrial processes, agriculture, and household products (e.g., polychlorinated biphenyls, polybrominated biphenyls, polycyclic aromatic hydrocarbons, some pesticides, components of plastics such as bisphenols and phthalates). Among these compounds there are some groups of chemicals still widely used and therefore constituting an important source of health hazards. The most important man-made endocrine disrupting compounds belong to three groups which met with great interest in last years, i.e., phthalates, bisphenols (mainly bisphenol A), and alkylphenols (used mainly as ethoxylates). Decades of their production and usage led to considerable contamination of the environment. They are found in water, air, soil, both animal and plant food. Therefore, growing number of studies are devoted to their degradation, biodegradation, and removal from the environment. Present studies on the biodegradation of phthalates, bisphenols, and alkylphenol derivatives aim mainly at testing of selected bacterial strains of different lineage including some Bacillus sp., Gordonia sp., Pseudoxanthomonas sp., Sphingomonas sp., and Rhodococcus sp. bacteria as well as other bacterial strains. Tests with fungi like Aspergillus sp. and Polyporus sp. or fungal enzymes like laccases are also carried out. Ultimately, understanding metabolic pathways of diverse species and genes involved in the biodegradation may help in constructing bacterial or fungal strains through usage of genetic engineering for effective removal of selected endocrine disrupting compounds. On the other hand, studies on removal of these contaminants from the environment were also undertaken. Biodegradation in natural waters, including seawater and in soil and sediments was tested to gain information on possibility of their removal from contaminated areas.
... The U.S. Environmental Protection Agency (EPA) has published a reference dose (RfD, 0.05 mg/kg/day) for BPA as the acceptable daily intake (ADI) for BPA through food additive use. Oral gavage was selected as the administration route, as in humans the uptake of BPA takes place mainly from food products [6][7][8][9][10] . BPA application took place from day 1 to 7 of pregnancy, being day 0 defined as the day at which a vaginal plug was registered. ...
Article
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Endocrine disrupting chemicals are long suspected to impair reproductive health. Bisphenol A (BPA) has estrogenic activity and therefore the capacity of interfering with endocrine pathways. No studies dissected its short-term effects on pregnancy and possible underlying mechanisms. Here, we studied how BPA exposure around implantation affects pregnancy, particularly concentrating on placentation and uterine remodeling. We exposed pregnant female mice to 50 µg/kg BPA/day or 0.1% ethanol by oral gavage from day 1 to 7 of gestation. High frequency ultrasound was employed to document the presence and size of implantations, placentas and fetuses throughout pregnancy. Blood velocity in the arteria uterina was analyzed by Doppler measurements. The progeny of mothers exposed to BPA was growth-restricted compared to the controls; this was evident in vivo as early as at day 12 as analyzed by ultrasound and confirmed by diminished fetal and placenta weights observed after sacrificing the animals at day 14 of gestation. The remodeling of uterine spiral arteries (SAs) was considerably impaired. We show that short-term exposure to a so-called "safe" BPA dose around implantation has severe consequences. The intrauterine growth restriction observed in more than half of the fetuses from BPA-treated mothers may owe to the direct negative effect of BPA on the remodeling of uterine SAs that limits the blood supply to the fetus. Our work reveals unsuspected short-term effects of BPA on pregnancy and urges to more studies dissecting the mechanisms behind the negative actions of BPA during early pregnancy.
... Aminolysis of polycarbonate can occur with 50 mM solutions of methionine and adjusted to pH 11 by sodium hydroxide at lower temperatures of 37°C. [227][228][229] The migration rates range from 0.38 to 0.49 mg/L/day and corrected for the realistic surface to volume ratio of baby bottles of about 8/dm, 0.11-0.14 mg/L/day. ...
... (Yehye et al., 2015) BPA is a monomer for polycarbonate and is known to leach from this material. (Sajiki and Yonekubo, 2004). DEHP was the most common plasticizer for polyvinyl chloride (PVC) but it is banned for consumer products and rarely found today as an extractables in (Bui et al., 2016) In addition, it is still used in medical products such as sampling bags for donor blood and storage of blood products. ...
Article
This article demonstrates, on a quantitative level, that leachables - potentially accumulated during a biopharmaceutical manufacturing process - will be significantly reduced/removed during four key downstream process steps: cell harvest using centrifugation or depth filtration, sterile filtration and virus filtration. Eight common leachables model compounds (LMCs) were spiked into typical feed solutions containing buffer and proteins and were analyzed post-processing in the supernatant or filtrates by HPLC-UV. The clearance rates were calculated as the quotient between the scavenged and initially spiked amount of each leachable. High clearance rates were found for hydrophobic LMCs for all investigated downstream operation steps. It is shown that the removal of cells and cell debris from a culture broth reduces the amount of LMCs almost completely after centrifugation or depth filtration. Also, sterilizing-grade and virus filtration provided a high scavenger effect to most of the LMCs. In contrast, only one hydrophilic acid was not significantly scavenged by the described operations. The possibility to include leachables sinks to a process qualification and risk mitigation concept is explained.
... The high pH combined with a high temperature can lead to degradation of PC material. It was also stated bySajiki and Yonekubo (2004) that basic pH provokes the degradation of PC material leading to the increased migration values from the material. ...
... One example is bisphenol-A, an estrogen disrupter that affects invertebrate and vertebrate development and reproduction (reviewed by Rubin 38 ), and previously shown to be released from plastic tanks made of polycarbonate or polysulfone. 39,40 If reused, plastic components of the housing system could also leach out some chemicals that became adsorbed onto their surface in previous experiments. Although this has not been yet reported in the literature, plastic polymers used in commercial housing systems may also release micrometric plastic particles that could interfere with the experiments. ...
Article
Many anthropogenic chemicals and plastic debris end up in the aquatic ecosystem worldwide, representing a major concern for the environment and human health. Small teleosts, such as zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes), offer significant advantages over classical animal models and are currently used as first-line organisms to assess environmental risks associated with many aquatic toxicants. Toxicological studies require the use of inert materials and controlled conditions. Yet, none of the available commercialized systems is adequate to assess the toxic effect of microplastics, because they contain components made of plastic polymers that may release micrometric plastic particles, leach manufacturing compounds, or adsorb chemicals. The ZEB316 stand-alone housing system presented in this study is meant to be a cost-effective and easy-to-built solution to perform state-of-the-art toxicological studies. It is built with inert and corrosion-resistant materials and provides good housing conditions through efficient recirculation and filtration systems. Assessment of water parameters and fish growth performance showed that the ZEB316 provides housing conditions comparable to those available from commercial housing systems.
... Ayrıca alkali ortamlarda özellikle yüksek sıcaklıkta hidroliz olayı daha hızlı gerçekleşmektedir. Bazı çalışmalarda alkali ortamlarda yüksek sıcaklıktaki suyla temas halinde olduğunda PC malzemenin hidrolitik depolimerizasyonunun arttığı ve buna bağlı olarak da BPA migrasyon değerlerinin yüksek olduğu gösterilmiştir [44,48,66,[70][71][72][73]. PC malzemelerde kullanım durumunun, polimerin degradasyonununda UV ışıktan bile daha etkili olduğu ve çok fazla kullanılmış olan PC malzemelerin kullanılmaması gerektiği de belirtilmektedir [73.] ...
... Bisphenol A is not an isolated chemical that leaches out from plastics. Bisphenols are a group of related chemicals that leaches out from the plastics [10][11][12]. We can take the example of Bisphenol B. ...
... What attract attention are especially marine plastic litter on the global scale presently and harm to marine animals. We should also recognize that plastic additives, such as bisphenols, phthalates, and phosphate flame retardants, have endocrine-disrupting properties as discussed in detail in previous chapters and are released from products [66]. ...
Chapter
The Minamata Convention was established following the Minamata disaster. To protect humans and the environment from persistent organic pollutants, the Stockholm Convention was established. However, there are many remaining chemicals with potential hazardous properties so that we must speed up and shorten the time to take action for such chemicals. Emerging environmental hazards including toxic chemicals are a threat to child health. A considerable number of birth cohorts have been recently established, and evidence reveals that there are certain adverse associations between environmental chemical exposures in utero and adolescent and children’s health. However, there are remaining agenda in preventing exposure of children to hazardous chemicals. We have pointed out challenges in future studies on (1) other risk factors that are not comprehensively addressed in this book, (2) mixture exposure, (3) genetics, (4) biomolecular approaches, (5) birth cohorts and consortiums, and (6) inclusion of environment into the original Developmental Origins of Health and Disease concept, as well as (7) long-term follow-up. The United Nations set the sustainable development goals. We should act together to create cleaner and safer environments for children by preventing exposure to chemical hazards, which will contribute to a healthier, more secure, and sustainable future for the world.
... Nonetheless, since the 1950's, BPA has been produced in large quantities, due to many factors such as its cost-efficient method of producing products, including plastic bottles, food containers, thermal receipts, and dental sealants [6]. Early research demonstrated that BPA had low toxicity and was rapidly metabolized, ultimately leading to safety approval of use in plastic production [11]. It was later found in both in vivo and in vitro studies that BPA acts as an endocrine disruptor, leading to adverse endocrine effects such as increased prostate weight, growth of mammary glands, and altered postnatal development; therefore, challenging previous beliefs that BPA was safe at low doses [12]. ...
Article
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Bisphenol A (BPA) and bisphenol S (BPS) are environmental contaminants that have been associated with the development of insulin resistance and type 2 diabetes (T2D). Two organs that are often implicated in the development of insulin resistance are the skeletal muscle and the adipose tissue, however, seldom studies have investigated the effects of bisphenols on their metabolism. In this review we discuss metabolic perturbations that occur in both the skeletal muscle and adipose tissue affected with insulin resistance, and how exposure to BPA or BPS has been linked to these changes. Furthermore, we highlight the possible effects of BPA on the cross-talk between the skeletal muscle and adipose tissue.
... MPs are undoubtedly considered as sources of chemical contaminants, owing to the release of monomers and oligomers in the aging process ( Chen et al., 2019a ;Guo et al., 2020 ;Liu et al., 2020a ;Liu et al., 2019b ). Evidence from numerous studies has reported that bisphenol A (BPA), the monomer of PC plastics, which is one of the prevailing endocrine disrupting compounds (EDCs), will be leached out from PC in seawater and freshwater environments ( Notardonato et al., 2019 ;Sajiki and Yonekubo, 2004 ;Xu et al., 2019 ). Despite that BPA is prohibited to be added into PC baby bottles and other food containers ( Erickson, 2011 ), diverse PC applications still utilize BPA as raw material. ...
Article
Bisphenol A polycarbonate (BPA PC) is a kind of widely used engineering plastics. However, excessive usage causes the production of plastic wastes, following property changes of polymers and high risks of released chemicals during outdoor weathering. In this study, we systematically investigated the pho- toaging behavior of PC microplastics (MPs) in aquatic environment and evaluated the potential risk of released intermediates. Light irradiation along with mechanical abrasion facilitated the fragmentation of PC MPs and stimulated photooxidative modification during 640 h of ultraviolet (UV) exposure. Continu- ous degradation of the polymer was accompanied with dramatic decline of molecular weight. Also, BPA was released from irradiated PC MPs with a trend of an initial rapid increase followed by a decrease ver- sus the irradiation time, and the maximum concentration of dropped BPA was detected up to 652.80 ±72.89 μg/g (43.39% and 56.61% respectively in particles and leachates). However, the releasing amount of BPA in the leachate merely occupied 2.7% of the total organic carbon (TOC) leached out, suggesting that a great number of unknown organic products were produced other than BPA. Liquid chromatography- time-of-flight-mass spectrometry (LC-TOF-MS) analysis showed that these organic compounds forming MPs-derived dissolved organic matter (MPs DOM) were partly composed of 4,4’-dihydroxybenzophenone (DHB), p-hydroxybenzoic acid (p-HBA) and methyparaben (MeP), which would also contribute to the es- trogenic activity. The degradation pathway of PC MPs was elaborated with the photolysis process of PC dimer and BPA, and the remarkable photoaging of PC MPs was mainly dominated by the generated reac- tive oxygen species (ROS). The findings of this study indicated that understanding the photoaging process of PC MPs was vital to evaluate their integral cumulative estrogenic activity in aquatic environment, and further highlighted the notable possible risks of plastic leachates to exposed biota.
... BPA is a synthetic estrogen agonist used in manufacturing everyday products. It can be detected in animals and humans in almost every system, organ, tissue, and cell, and is linked to destructive consequences in female fertility, such as diseases and cancers [2][3][4]. BPA has been linked to increased primordial follicle recruitment, a decrease in the number of viable oocytes and decreased antral follicular growth (reviewed in [5]). Our group has reported poor oocyte and embryo quality with lower cleavage and blastocyst rates as well as alterations in chromosome alignment, sex ratios, spindle formation, apoptosis levels, and gene expression in response to BPA treatment of in vitro produced bovine oocytes [3,6]. ...
Article
Full-text available
Bisphenol A (BPA) and its alternative, bisphenol S (BPS), are widespread endocrine disrupting compounds linked in several studies to poor female fertility. Sufficient oocyte competence and subsequent embryo development are highly dependent on oocyte maturation, an intricate process that is vulnerable to BPA. These effects as well as the effects of its analog, BPS, have not been fully elucidated. Although the harmful consequences of bisphenols on the reproductive system are largely due to interferences with canonical gene expression, more recent evidence implicates noncoding RNAs, including microRNAs (miRNA), as significant contributors. The aim of this work was to test the hypothesis that abnormal expression of key miRNAs during oocyte maturation and embryo development occurs following BPA and BPS exposure during maturation. Using qPCR, primary and mature forms of miR-21, -155, -34c, -29a, -10b, -146a were quantified in an in vitro bovine model of matured cumulus-oocyte complexes, fertilized embryos, and cultured cumulus cells after exposure to BPA or BPS at the LOAEL dose (0.05 mg/mL). Expression of miR-21, miR -155, and miR-29a were markedly increased (P = 0.02, 0.04, <0.0001) while miR-34c and miR-10b were decreased (P = 0.01, 0.01), after BPA treatment. miR-146a expression remained stable. BPS had no effects, suggesting may not exert its actions through these six miRNAs examined. Overall, this study indicates that BPA effects are likely miRNA specific rather than a global effect on miRNA synthesis and processing mechanisms and that its analog, BPS, may not possess the same properties required to interfere with these miRNAs during bovine oocyte maturation.
... Our results are consistent with those from a previous study, where human intakes of BPA were 1−2 orders of magnitudes lower than the intakes estimated from the WBE. 45 This shows that urinary excretion is not a major source for the BPA and BPS in wastewater in South East Queensland, and other sources such as direct leaching from plastic products 57 and industrial input 58 are likely the primary sources of bisphenols that reach WWTPs. Lopardo et al. 28 focused on estimating population wide total daily intake of BPA from free BPA and BPA sulphate in the wastewater. ...
Article
Health concerns and related regulation of bisphenol A (BPA) in some countries have led to an increase in the production and use of unregulated and poorly understood BPA analogues, including bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), and bisphenol AF (BPAF). To assess the temporal trends of human exposure to BPA analogues, urine and wastewater samples were collected from South East Queensland, Australia between 2012 and 2017 and analyzed for five bisphenols using validated isotope dilution liquid chromatography tandem mass spectrometry methods. BPA and BPS were the predominant bisphenols detected in both urine and wastewater samples, with median concentrations of 2.5 and 0.64 μg/L in urine and 0.94 and 1.1 μg/L in wastewater, respectively. BPB, BPF, and BPAF had low detection frequencies in both urine and wastewater samples. Concentrations of BPA in both urine and wastewater decreased over the sampling period, whereas concentrations of BPS increased, suggesting that BPS has become a BPA replacement. The contributions of urinary excretion to wastewater were calculated by the ratio of daily per capita urinary excretion to wastewater-based mass loads of bisphenols. Urinary BPA and BPS contributed to less than 1% of the load found in wastewater, indicating that much of the BPA and BPS originates from other sources.
... Besides BPA and phosgene, there is another type of compound that goes into the building of the polycarbonate chain called chain terminator. Chain terminator is added to cap the ends of the chains, limiting how long they can grow (Sajiki and Yonekubo, 2004). ...
Article
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BPA is an EDC which is continuously released into the environment because of its extensive usage as plasticizer and other industrial applications. The present study establishes BPA induced alterations in mitochondrial marker enzymes and hence cause mitochondrial dysfunction. Studies were performed to evaluate the histopathological changes in tissue on exposure to different doses of BPA for different time periods. Light microscopic examination of samples was done to evaluate the possible changes caused by treatment of different doses of BPA. After getting the results in light microscopy the changes and damage caused by BPA ultra-structurally were observed. Light microscopic study showed that BPA exposure for short duration of 7 days did not resulted in significant change in histology of Rat of treated animals. Light microscopic observations showed that low doses of BPA (5 and 10 mg/kg body weight) exposure for 14 days caused reduction in the number of cells in the layers of seminiferous tubules. Highest dose of BPA treatment for 14 days caused much damage to the seminiferous tubules. There were many ultra-structural changes found in the treated groups as compared to the control group. Hence it can be stated that due to the toxic effect of BPA the mitochondrial marker enzymes have shown marked reduction in their activities. Keywords: BPA, EDCs, Light microscopic, Mitochondria and Toxicity.
Article
We report detection of bisphenol A (BpA) in drinking water using a compact surface plasmon resonance (SPR) sensor and binding inhibition detection format. This method does not require any special treatment of water samples – the analyzed water is just passed through a 0.22μm filter and its pH and salt content are adjusted to those of the phosphate buffered saline (PBS). We demonstrate that this approach allows detection of BpA in drinking water down to 40pg/ml in less than 35min.
Article
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Unlabelled: Polymeric and elastomeric materials are commonly encountered in medical devices and packaging systems used to manufacture, store, deliver, and/or administer drug products. Characterizing extractables from such materials is a necessary step in establishing their suitability for use in these applications. In this study, five individual materials representative of polymers and elastomers commonly used in packaging systems and devices were extracted under conditions and with solvents that are relevant to parenteral and ophthalmic drug products (PODPs). Extraction methods included elevated temperature sealed vessel extraction, sonication, refluxing, and Soxhlet extraction. Extraction solvents included a low-pH (pH = 2.5) salt mixture, a high-pH (pH = 9.5) phosphate buffer, a 1/1 isopropanol/water mixture, isopropanol, and hexane. The resulting extracts were chemically characterized via spectroscopic and chromatographic means to establish the metal/trace element and organic extractables profiles. Additionally, the test articles themselves were tested for volatile organic substances. The results of this testing established the extractables profiles of the test articles, which are reported herein. Trends in the extractables, and their estimated concentrations, as a function of the extraction and testing methodologies are considered in the context of the use of the test article in medical applications and with respect to establishing best demonstrated practices for extractables profiling of materials used in PODP-related packaging systems and devices. Lay abstract: Plastic and rubber materials are commonly encountered in medical devices and packaging/delivery systems for drug products. Characterizing the extractables from these materials is an important part of determining that they are suitable for use. In this study, five materials representative of plastics and rubbers used in packaging and medical devices were extracted by several means, and the extracts were analytically characterized to establish each material's profile of extracted organic compounds and trace element/metals. This information was utilized to make generalizations about the appropriateness of the test methods and the appropriate use of the test materials.
Chapter
An emerging class of pervasive pollutants, microplastics are being increasingly detected in almost all the environmental matrices. Microplastics are plastic particles having a size of less than 5 mm, either formed from the disintegration of large plastics in the environment due to natural and anthropogenic factors, named as secondary microplastics, or manufactured that way for industrial and commercial uses, namely primary microplastics. They occur in a variety of shapes such as beads, fibres, fragments, foams, etc. in nature. As an emerging pollutant, they are gaining popularity among researchers due to massive abundance and yet to be identified potential impacts on different tiers of the ecosystem. This chapter reviews the occurrence and abundance of microplastics in all the environmental compartments, various detection methods, different sources of generation, and their fate and transport in air, water, and soil. A discussion on current trends of their exposure levels on biota and ecotoxicological effects is also included. Further, the potential of microplastics as the carriers of other organic pollutants and leaching out of toxic chemicals from microplastics are also reviewed.
Article
Bisphenol A (BPA), a monomer used in the production of plastics and epoxy resins, is ubiquitously present in the aquatic environment. BPA is considered a weak estrogen in fish, but the effects of this chemical on early developmental events are far from clear. We tested the hypothesis that BPA accumulation in eggs, mimicking maternal transfer, disrupts growth hormone/insulin-like growth factor (GH/IGF) axis function, leading to defects in larval growth in rainbow trout. Trout oocytes were exposed to 0 (control), 0.3, 3, and 30 μg ml−1 BPA for 3 h, which led to an accumulation of around 0, 1, 4 and 40 ng BPA per egg, respectively. All treatment groups were fertilized with clean milt and reared in clean water for the rest of the experiment. The embryo BPA content declined over time in all groups and was completely eliminated by 42 days post-fertilization (dpf). Hatchlings from BPA accumulated eggs had higher water content and reduced total energy levels prior to first feed. There was an overall reduction in the specific growth rate and food conversion ratio in larvae reared from BPA-laden eggs. BPA accumulation disrupted the mRNA abundance of genes involved in GH/IGF axis function, including GH isoforms and their receptors, IGF-1 and -2 and IGF receptors, in a life stage-dependent manner. Also, there was a temporal disruption in the mRNA level of thyroid hormone receptors in the larvae raised from BPA-laden eggs. Altogether, BPA accumulation in eggs, mimicking maternal transfer, affects larval growth and the mode of action involves disruption of genes involved in the GH/IGF and thyroid axes function in trout.
Article
The advanced oxidation process (AOP) through ultrasound-assisted photocatalytic degradation has attracted much attention in removing emerging contaminants. Herein, CoFe2O4-GO and CoFe2O4-g-C3N4 nanocomposites were synthesized using the ultrasound-assisted co-precipitation method. TEM, XRD, XPS, EDS, SEM, and FT-IR techniques characterized the structural, morphological, and chemical properties of the synthesized nanocomposites. The analyses showed that CoFe2O4 structure was nano-sized and distributed more homogeneously in graphene oxide (GO) layers with oxygenated functional groups than graphitic carbon nitride (g-C3N4). While the efficiency of composite catalysts, as photocatalysts, for degradation of bisphenol-A (BPA) was low in the visible region in the presence of persulfate, their catalytic efficacy was higher with sonolytic activation. The addition of persulfate as an oxidant remarkably enhanced the target pollutant degradation and TOC removal of BPA solution. Both composite catalysts showed 100 % BPA removal with the synergistic effect of visible region photocatalytic oxidation and sonocatalytic oxidation in the presence of persulfate at pH 6.8. In ultrasound-assisted photocatalytic oxidation of BPA, the highest mineralization efficiencies were obtained at 2 h treatment time, pH 6.8, 16 mM PS, catalyst dosages of 0.1 g/L CoFe2O4-GO, and 0.4 g/L CoFe2O4-g-C3N4 as 62 % and 55 %, respectively. An effective catalyst was obtained by reducing e⁻/h⁺ recombination and charge transfer resistance by decorating the GO layers with CoFe2O4.
Article
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Objective: To quantitatively determine the bisphenol-A (BPA) leached from orthodontic materials during simulated intraoral exposure. Materials and methods: Samples of orthodontic materials were subjected to simulated abrasion, immersion in artificial saliva, thermal shock via temperature cycling, and simulated intraoral exposure. Sample aliquots were collected for up to 2 weeks after artificial saliva immersion, derivatized, then analyzed for BPA by gas chromatography/mass spectroscopy. Results: Quantifiable amounts of leached BPA were observed from a thermoformed orthodontic retainer material (7.63 µg/g of material) and an orthodontic adhesive (2.75 µg/g of material). BPA leaching was only observed within the first 3 days of artificial saliva immersion. Conclusions: Under the test conditions, BPA was observed to leach from two orthodontic materials. While the quantities of leached BPA were below the reference dose for daily intake, existing data of low-dose effects and medical disorders associated with elevated urinary BPA levels suggest that BPA exposure, and thus the use of the leaching materials identified in this study, should be reduced or eliminated.
Article
Photocatalytic degradation mechanism of the polycarbonate(PC)/TiO2 composite films was studied under the ambient air condition in order to investigate the feasibility of the PC/TiO2 composite as a photodegradable polymer. TiO2 composition in the PC/TiO2 composite was changed from 0 wt% to 4 wt%. Photodegradation behaviors of the composite films were compared with that of the pure PC films by performing the weight loss monitoring under UV irradiation, FTIR spectroscopy, color measurement analysis, and XPS analysis. The weight loss rate of the PC/TiO2 composite film (33% weight loss after 300 h) with 4 wt% TiO2 was twice as high as the pure PC films (14% weight loss after 300 h). The increase in the FTIR hydroxyl peak, and carbonyl peak intensity and the yellowing observation during the photodegradation were due to the formation of the photoproducts (aliphatic, aromatic chain-ketones, aromatic, and OH radical) and the structural modification of polycarbonate. XPS analysis of composite film showed the photodegradation of the polymer surface and TiO2 particles exposure on the surface of the composite films matrix. POLYM. COMPOS., 2014. © 2014 Society of Plastics Engineers
Article
In this paper, bisphenol A (BPA) was successfully deposited on an indium–tin oxide (ITO) electrode by the method of multiple sweep voltammetry. The BPA deposition was found to be affected by the upper potential limit of the multiple sweep voltammetry, the voltammetric sweep number, pH value and BPA concentration. The resulting BPA deposit showed excellent redox activity in an appropriate potential range between −0.2V and 0.4V as well as high ionic–electronic conductivity, revealed by ex-situ voltammetry and scanning electrochemical microscopy. On the basis of redox reactions of the BPA deposit on the ITO electrode, an electrochemical sensor for monitoring the removal of BPA was further proposed. The linear response range was found to be between 0.5μM and 50μM with a detection limit of 0.4μM (S/N=3). The results from this study have provided an alternative in situ method for monitoring of BPA removal.
Article
Room temperature ionic liquids (RTILs) are emerging as a new class of 'green' solvents for use in a wide range of chemical processes. RTILs can sensitize or quench fluorescence of organic chemicals and their interactions still remain unclear, especially for weakly fluorescent chemicals. Herein, we report the effects of six RTILs on the fluorescence behavior of bisphenol A (BPA). The fluorescence intensities (FIs) of BPA in a RTIL-acetonitrile system were significantly quenched compared to acetonitrile. The quenching effect was stronger for [CnMIM]BF4 than [CnMIM]PF6. A decreasing trend of fluorescence lifetime (FL) of BPA was observed for [C6MIM]PF6 (4.26 to 3.86 ns) and [C14MIM]PF6 (4.15 to 3.78 ns) with increasing RTIL concentrations in the range of 1-10 mM. The quenching mode was consistent with a static quenching mechanism based on the consistency of FL and FI results. The emission bands of BPA and RTILs did not interfere with each other when RTILs were used as the solvent. The investigated RTILs enhanced the FIs of strongly fluorescing chemicals (12.0 ~ 19.0-fold for norfloxacin and 6.1 ~ 8.5-fold for dansyl chloride), but quenched those of weakly fluorescing chemicals (BPA). These results demonstrate that RTILs have different fluorescent effects on organic chemicals with different fluorophores. The interactions between RTILs and BPA result from many factors in addition to viscosity, such as solvent electrostatic dielectric constant, refractive index, density, polarization and molecular interaction. These results provide a theoretical foundation for application of RTILs in the analysis of weakly fluorescing chemical.
Article
Environmental contextCarbon nanotubes are added to polymers such as polycarbonate and epoxy to form nanocomposites with enhanced material properties. Environmental factors including temperature, UV light exposure and pH have the potential to degrade these composites and increase the release of toxic polymer-associated chemicals. This study investigates how carbon nanotube loading decreases the release of known endocrine-disrupting compounds, bisphenol A and 4-tert-butylphenol, from polymer nanocomposites under simulated weathering environments. AbstractNanoparticles such as carbon nanotubes are increasingly added to polymer matrices to improve tensile strength and electrical and thermal conductivity, and to reduce gas permeability. During use and after disposal, these plastic nanocomposites (PNCs) are degraded into microplastics by physical and chemical processes including mechanical abrasion, UV light exposure, hydrolysis and oxidation. Such polymers have the potential to enter aquatic environments and release potentially hazardous polymer-associated chemicals and transformation products. This work identifies and quantifies polymer-associated chemicals leached from polymers and nanocomposites during simulated environmental exposure. Epoxy and polycarbonate PNCs containing single-walled carbon nanotube (SWCNT) loadings ranging from 0 to 1 wt-% were exposed to water for 5 days, and the release of the chemicals bisphenol A (BPA) and 4-tert-butylphenol (TBP) was measured. The role of UV exposure, pH, temperature and natural organic matter in regulating chemical release was also investigated. Temperature, pH and UV light were found to be the most significant factors influencing release of TBP and BPA from PNCs. Additionally, increasing carbon nanotube loading in both polycarbonate and epoxy composites was found to decrease the release of these phenolic chemicals. A 0.3% higher SWCNT loading decreased the release of BPA 45±18%, and a 1% SWCNT loading decreased chemical release from epoxy by 48±26% for BPA and 58±8% for TBP. This information provides important data that can be used to help assess the risks posed by SWCNT polymer nanocomposites in aqueous environments, particularly as they age and are transformed.
Technical Report
The present report, conducted by the Global Marine and Polar Programme of the International Union for the Conservation of Nature (IUCN) within the framework of the “Action for an Ocean Free of Microplastics” project, with the participation of the Race for Water Foundation and the support of Svenska Postkodlotteriet, aims to provide to economic actors, policy makers and the public at large, a comprehensive overview of the current state of knowledge of the effects of plastics on marine environments, organisms and ecosystems.
Article
Background: In this study, the authors quantitatively determined the bisphenol A (BPA) leached from intraoral materials during simulated intraoral exposure. Methods: The authors subjected samples of intraoral materials to simulated abrasion, immersion in artificial saliva, thermal shock via temperature cycling, and simulated intraoral exposure. The authors collected sample aliquots for up to 2 weeks after artificial saliva immersion, derivatized, and then analyzed the aliquots for BPA by gas chromatography and mass spectroscopy. Results: Quantifiable amounts of leached BPA were observed from only 1 of 13 intraoral materials tested: a silicone baby bottle nipple (20 micrograms). BPA leaching was only observed after 3 days of artificial saliva immersion, with no additional leaching thereafter. Conclusions: Under the test conditions, BPA was observed to leach from a silicone baby bottle nipple. Practical implications: Although the quantities of leached BPA were below the reference dose for daily intake, investigators have shown a possible association between low levels of BPA and many medical disorders. BPA exposure, and thus the use of the leaching material identified in this study, should be reduced or eliminated.
Research
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IMO/FAO/UNESCO-IOC/UNIDO/WMO/IAEA/UN/UNEP/UNDP Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection GESAMP. Rep. Stud. GESAMP No. 90, 96 p.
Article
The plastic additive bisphenol A (BPA) is commonly found in landfill leachate at levels exceeding acute toxicity benchmarks. To gain insight into the mechanisms controlling BPA emissions from waste and waste handling facilities, a comprehensive field- and lab-campaign was conducted to quantify BPA in solid waste-materials (glass, combustibles, vehicle fluff, waste electric and electronic equipment, plastics, fly ash, bottom ash and digestate), leachate water and atmospheric dust from Norwegian sorting-, incineration- and landfilling-facilities. Solid waste concentrations varied from below 0.002 mg/kg (fly ash) to 188 ± 125 mg/kg (plastics). A novel passive sampling method was developed to, for the first time, establish a set of waste-water partition coefficients, KD,waste for BPA, and to quantify differences between total and freely-dissolved concentrations in waste-facility leachate. Log-normalized KD,waste (L/kg) were similar for all solid waste materials (from 2.4-3.1), excluding glass and metals, indicating BPA is readily leachable. Leachate concentrations were similar for landfills and WEEE/Vehicle sorting facilities (from 0.7 to 200 µg/L), and dominated by the freely-dissolved fraction, and not bound to (plastic) colloids (agreeing with measured KD,waste values). Dust concentrations ranged from 2.3 to 50.7 mg/kgdust. Incineration appeared an effective way of reducing BPA concentrations in solid waste, dust and leachate.
Article
Despite many studies on the effects of perinatal Bisphenol A (BPA) exposure on the brain, its effects on brain estrogen receptor (ERα) expression during puberty remain unclear. Here, mice were injected subcutaneously with BPA (50μg/kg), estradiol (10μg 17β-E2/kg) or oil (0.05ml sesame oil) daily during puberty (postnatal days 23-30). Immunohistochemistry was used to examine changes in ERα immunoreactive neurons in different brain regions. Compared to control animals, pubertal exposure to BPA significantly increased ERα immunoreactive neurons in the bed nucleus of the stria terminalis (BST), arcuate hypothalamic nucleus (Arc), ventromedial hypothalamic nucleus (VMH) and medial amygdaloid nucleus (MeA) in females. E2 exposure during puberty also increased ERα immunoreactive neurons in the lateral septum (LS) of females. No effect was detected in males. These results indicate that the effects of estrogenic chemicals on ERα immunoreactive neurons are sex-dependent.
Article
A sensitive electrochemical sensor for determining bisphenol A(BPA) was designed. The sensor was a glassy carbon electrode modified with the surfactant cetyltrimethylammonium bromide and the ionic liquid 1-decyl-3-methylimidazolium tetrafluoroborate. The ability of the new sensor to measure BPA was investigated in cyclic voltammetry experiments. Under optimized conditions, the sensor gave a linear response range for BPA of 2.19×10−7―3.28×10−5 mol/L and a detection limit of 7.31×10−8 mol/L(S/N=3). BPA could be determined with a lower detection limit, a wider linear range, and more sensitivity using the sensor than using other electrochemical sensors or high performance liquid chromatography with UV detection. The new sensor was used to determine BPA in tap water with recoveries of 97.5%―98.7% and a relative standard deviation <2.9%. The results show that the sensor can be used to determine trace BPA concentrations in tap water.
Article
Current initiatives for waste-handling in a circular economy favor prevention and recycling over incineration or landfilling. However, the impact of such a transition on environmental emissions of contaminants like bisphenol A (BPA) during waste-handling is not fully understood. To address this, a material flow analysis (MFA) was constructed for selected waste categories in Norway, for which the amount recycled is expected to increase in the future; glass, vehicle, electronic, plastic and combustible waste. Combined, 92 tons/y of BPA are disposed of via these waste categories in Norway, with 98.5% associated with plastic and electronic waste. During the model year 2011, the MFA showed that BPA in these waste categories was destroyed through incineration (60%), exported for recycling into new products (35%), stored in landfills (4%) or released into the environment (1%). Landfilling led to the greatest environmental emissions (up to 13% of landfilled BPA), and incinerating the smallest (0.001% of incinerated BPA). From modelling different waste management scenarios, the most effective way to reduce BPA emissions are to incinerate BPA-containing waste and avoid landfilling it. A comparison of environmental and human BPA concentrations with CoZMoMAN exposure model estimations suggested that waste emissions are an insignificant regional source. Nevertheless, from monitoring studies, landfill emissions can be a substantial local source of BPA. Regarding the transition to a circular economy, it is clear that disposing of less BPA-containing waste and less landfilling would lead to lower environmental emissions, but several uncertainties remain regarding emissions of BPA during recycling, particularly for paper and plastics. Future research should focus on the fate of BPA, as well as BPA alternatives, in emerging reuse and recycling processes, as part of the transition to a circular economy.
Chapter
Additives and monomers are integral components of plastics or polymers. Bisphenol A (BPA), nonylphenol (NP), and polybrominated diphenyl ethers (PBDEs) are the common monomer and additives used primarily to improve the quality of plastic materials. They are used as antioxidants, stabilizers, plasticizers, and flame retardants in plastics that are in turn used in the manufacture of a wide range of consumer and industrial products. In this chapter, the release of BPA, NP, and PBDEs from waste plastic materials is presented. A brief background of the physical and chemical characteristics of BPA, NP, and PBDEs, and other factors that influence the release of these monomer and additives from plastics, is also discussed. The overview of the consequential occurrence of these compounds in leachates from landfills and/or municipal solid waste (MSW) dumping sites provides evidence on the release of BPA, NP, and PBDEs from dumped plastic materials.
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This study was to investigate developmental toxicity of some selected low molecular weight antioxidants, by utilising sea urchin embryos and gametes as model system. Sea urchin embryos or sperm were exposed at different developmental stages to L-methionine or some selected low molecular weight antioxidants: a) N-acetylcysteine; b) L-carnosine; c) L-homocarnosine, and d) L-anserine. L-methionine displayed developmental toxicity at levels > or = 10(-5) M, whereas the other agents tested were mostly active at levels > or = 10(-4) M. When embryos were exposed to 10(-4) M L-methionine or N-acetylcysteine at different developmental stages, the most severe effects were exerted by early exposures (0 to 2 hr after fertilisation), whereas later exposures turned to lesser or no effects. Cytogenetic analysis of L-methionine-exposed embryos showed a significant mitogenic effect and increase of mitotic aberrations. Fertilisation success was decreased by L-methionine (10(-6) M to 10(-3) M) added at the moment of fertilisation, with increasing developmental and cytogenetic abnormalities in the offspring. The formation of reactive oxygen species in embryos and gametes was determined by: a) analysing the DNA oxidative product, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and b) luminol-dependent chemiluminescence. The results showed that: 1) 8-OHdG levels were increased during embryogenesis; 2) fertilisation was associated with a double-wave luminol-dependent chemiluminescence emission; 3) luminol-dependent chemiluminescence was maximal in cleavage, declining down to zero in plutei, and 4) an embryotoxic L-methionine or N-acetylcysteine level (10(-4) M) turned to a decrease in reactive oxygen species formation. The data suggest that L-methionine- or N-acetylcysteine-induced developmental toxicity is confined to early stages. A role for oxidative activity is suggested in modulating cell differentiation and embryogenesis, consistent with antioxidant-induced damage to early life stages.
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Twenty-four brands of plastic baby feeding bottles were purchased and all were found to be made of polycarbonate. Taking a batch of one representative sample, the polymer was tested for stability and possible release of bisphenol A following domestic practice of sterilization. Sterilization was by alkaline hypochlorite, steam, or washing in an automatic dishwasher at 65 degrees C with detergent. A total of 20 cycles of sterilization and subsequent food use were performed for each of the three procedures. Bisphenol A migration was in all cases not detectable in infant feed using a very sensitive method of liquid chromatography with fluorescence detection with a 0.03 mg/kg detection limit.
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The lipids of high density lipoproteins (HDL) are initially oxidized in preference to those in low density lipoprotein when human plasma is exposed to aqueous peroxyl radicals. In this work we report on the relative susceptibility of HDL protein and lipid to oxidation and on the role HDL's alpha-tocopherol (alpha-TOH) plays in modulating protein oxidation. Exposure of isolated HDL to either low fluxes of aqueous peroxyl radicals, Cu2+ ions, or soybean lipoxygenase resulted in the oxidation of apoAI and apoAII during the earliest stages of the reaction, i.e. after consumption of ubiquinol-10 and in the presence of alpha-TOH. Hydro(pero)xides of cholesteryl esters and phospholipids initially accumulated together with specific oxidized forms of apoAI and apoAII, separated by high pressure liquid chromatography. The specific oxidized forms of apoAI were 16 and 32 mass units heavier than those of the native apolipoproteins and contained 1 and 2 methionine sulfoxide residues per protein, respectively. The third methionine residue in apoAI, as well as Trp residues, remained unoxidized during the earliest stages of HDL oxidation examined. Exposure of isolated apoAI to peroxyl radicals, Cu2+, or soybean lipoxygenase resulted in nonspecific (for peroxyl radicals) or no discernible protein oxidation (Cu2+ and soybean lipoxygenase). This indicated that the formation of the specific oxidized forms of apoAI observed with native HDL was not the result of direct reaction of these oxidants with the apolipoprotein. In vitro and in vivo enrichment of HDL with alpha-TOH resulted in a dose-dependent increase in the extent of peroxyl radical-induced formation of HDL cholesteryl ester hydroperoxides (r = 0.96) and cholesteryl ester hydroxides (r = 0. 92), as well as the loss of apoAI (r = 0.96) and apoAII (r = 0.94). alpha-TOH enrichment also enhanced HDL lipid and protein oxidation induced by Cu2+ or soybean lipoxygenase. These results indicate that the earliest stages of HDL oxidation are accompanied by the oxidation of specific methionine residues in apoAI and apoAII and that in the absence of co-antioxidants, alpha-TOH can promote this process.
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Bisphenol A (CAS 85-05-7) may be released into the environment through its use and handling, and permitted discharges. BPA is moderately soluble (120 to 300 mg/L at pH 7), may adsorb to sediment (Koc 314 to 1524), has low volatility, and is not persistent based on its rapid biodegradation in acclimated wastewater treatment plants and receiving waters (half-lives 2.5 to 4 days). BPA is "slightly to moderately" toxic (algal EC50 of 1000 micrograms/L) and has low potential for bioaccumulation in aquatic organisms (BCFs 5 to 68). The chronic NOEC for Daphnia magna is > 3146 micrograms/L. Surface water concentrations are at least one to several orders of magnitude lower than chronic effects, with most levels nondetected.
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The authors critically surveyed research dealing with the release of resin components from dental composites and the potential of these agents to mimic or disrupt estrogenic cell responses. The studies reviewed included those on synthetic methods used to make bisphenol A glycidyl methacrylate, or BIS-GMA, and the biological effects of this resin in cell culture and animals. The estrogenic effect of bisphenol A was targeted because bisphenol A is present as an impurity in some resins (BIS-GMA) and as a degradation product from other resins (bisphenol A dimethacrylate, or BIS-DMA). The outcomes of this review revealed that short-term administration of BIS-GMA and/or bisphenol A in animals or cell cultures can induce changes in estrogen-sensitive organs or cells. However, considering the dosages and routes of administration and the modest response of estrogen-sensitive target organs, the authors conclude that the short-term risk of estrogenic effects from treatments using bisphenol A-based resins is insignificant. Long-term effects need to be investigated further. Commonly used dental resins should not be of concern to the general public; however, pharmacological evaluation of dental materials is needed to ensure biologically safe and therapeutically effective substances.
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To quantify the leaching of bisphenol A into water, various samples of plastic waste were cut into small pieces, soaked in water for two weeks at room temperature in the dark, and the concentration of bisphenol A in the water determined by gas chromatography/mass spectrometry (GC/MS). The amount of bisphenol A leached from the plastic wastes ranged from undetectable to 139 micrograms/g. The detection limit was 2 ng/g when 100 g of plastic waste was used. Polyvinyl chloride products yielded the highest concentrations because bisphenol A is used in its manufacture as a stabilizer.
The aim of this study was to establish an easy and accurate method for the determination of bisphenol-A (BPA) in the body liquid such as serum and urine. Two high-performance liquid chromatography (HPLC) systems, HPLC with electrochemical detector (ED), and HPLC with mass spectrometry (MS) using electrospray ionization (ESI) interface were used for the assay in the serum samples prepared with solid-phase extraction method. Water or EtOH at a concentration below 50% was suitable for the extraction of BPA from serum. The limit of detection of BPA was 0.2 ng ml(-1) for the HPLC-ED method and 0.1 ng ml(-1) for HPLC-MS. There was a good correlation between the data obtained by the two HPLC systems. BPA concentrations in healthy human serum were low (0-1.6 ng ml(-1)). From various commercial fetal bovine serum and sheep plasma, however, significant amounts of BPA were detected. Since no BPA was detected from sheep plasma immediately after collection, the high amounts of BPA were considered to be caused by the handling of blood during the preparation of the products after blood collection. In vitro study showed that the amount of BPA leached from polycarbonate tube into sheep plasma were 40 times larger than those into water and the leached amount of BPA depended on the temperature (37 degrees C>20 degrees C>5 degrees C).
Article
The reactivity of bisphenol A (BPA), diethylstilbestrol (DEST) 2,2'-biphenol (22'BP), 4,4'-biphenol (44'BP) and hydroquinone (HQ) as radical scavengers was examined in 2,2'-azobisisobutyronitrile (AIBN)- and benzoyl peroxide (BPO)-induced methyl methacrylate (MMA) polymerization with respect to kinetic considerations. The initial rate of polymerization (IRP) was found to decrease in the order: 44'BP > BPA, DEST > 22'BP > HQ, while the stoichiometric factor (n) of free radicals trapped by phenolic moiety decreased in the order: 44'BP (2.3) > HQ (2.0) > BPA, DEST (1.8) > 22'BP (0.8). It was found that BPA was a more highly efficient inhibitor than HQ and that HQ acts as a retarder at higher concentrations in the BPO system. The high activity of BPA indicated that BPA is probably oxidized by a radical interaction in the dental resin system.
Article
In order to ascertain whether an estrogenic bisphenol A is produced from bisphenol A-related monomers by chemical-induced hydrolysis and to clarify their hydrolytic mechanisms, bisphenol A dimethacrylate (Bis-DMA) and bisphenol A bis(glycidyl methacrylate) (Bis-GMA) were reacted with phosphoric acid, hydrochloric acid, and sodium hydroxide in methanol or methanol/water mixed media at 37 degrees C. Amounts of monomethacrylate intermediates as well as bisphenol A (BPA) were determined by the use of high-performance liquid chromatography (HPLC), and time-conversion curves of hydrolytic products were prepared. BPA and bisphenol A monomethacrylate were produced by acid-catalyzed hydrolysis of Bis-DMA. Bis-GMA was partly converted into monomethacrylate by phosphoric acid and into monomethacrylate and 2,2-bis[4-(2,3-dihydroxypropoxy) phenyl]propane (BHP) by hydrochloric acid. Hydrolytic reactions by sodium hydroxide were completed almost within 1 day, resulting in the production of BPA from Bis-DMA, and BHP from Bis-GMA. No BPA was formed from Bis-GMA by chemical-induced hydrolysis. The hydrolytic behaviors of these monomers were discussed.
Article
This study was designed to determine whether bisphenol A (BPA) is eluted from hemodialyzers in which polycarbonate and polysulfone based on BPA are used as materials. Four types of polysulfone hemodialyzer (PS hemodialyzer: PS-A, PS-B, PS-C and PS-D) and an ethylene-vinyl alcohol copolymer dialyzer (EVAL hemodialyzer) were used in this study. In the PS-C, PS-D and EVAL hemodialyzers, polycarbonate was used in the case headers at both ends of the hemodialyzer. In in vitro experiments, the hemodialyzers were filled with reverse osmotic water, and BPA concentrations were measured. Saline solution (200 ml) was then circulated through a blood circuit tube connected to the hemodialyzer, and BPA concentrations in the saline solution were measured. In in vivo experiments, BPA concentrations in whole blood samples from hemodialysis patients treated with PS-C (n = 3) and PS-D (n = 3) hemodialyzers were measured. In in vitro experiments, BPA was detected in the effluents of the PS-C, PS-D and EVAL hemodialyzers. In in vivo experiments, BPA was detected in whole blood samples from hemodialysis patients treated with the PS-D hemodialyzer (mean value, 0.77 ppb). This is the first report of BPA elution from hemodialyzers in which polycarbonate and polysulfone are used, and also the first report of detection of BPA in whole blood samples from patients on hemodialysis.
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A change in bisphenol-A (BPA) concentration leached from polycarbonate (PC) tube to the phosphatidyl ethanolamine (PhE)-containing water was compared to water only. Time-dependent increase in BPA concentration was observed in both samples at 37 degrees C. The leaching velocity of BPA to water was three times faster than that to PhE-containing water and BPA concentration in water reached to 55.8 ng/ml 5 weeks later. When BPA was determined immediately after BPA addition of various concentration of PhE up to 2.5mg/ml to water, the BPA recoveries were over 93%. But, when incubated at 37 degrees C for a special time, BPA concentration in PhE-containing water in glass tube decreased time-dependently. In the presence of H2O2, time and Fe3+ dose-dependent decrease in the BPA concentration particularly, a drastic decrease above 0.44 mM Fe3+ was observed. These results suggest that BPA would be decomposed by radical oxygen including lipoperoxides. An addition of serum prevented BPA decrease from radical oxygen to a great extent but could not recover the BPA decrease. Thiobarbituric acid (TBA) value, a good parameter of lipid oxidation, decreased gradually in the mixture of H9O2 and Fe3+ in the presence of BPA, implying an inhibition of lipid oxidation due to BPA oxidation by radical oxygen.
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In this study, (1) change in bisphenol-A (BPA) leached from polycarbonate (PC) tube to water samples at 37 degrees C, (2) effect of reactive oxygen species (ROS) produced by Fenton reaction on BPA recovery and thiobarbituric acid (TBA) value with or without generally existing environmental substances such as alcohol, lipids and NaCl, were investigated. Amounts of BPA leached from PC tube to water samples containing lipids possessing unsaturated fatty acid with high TBA values were significantly lower than the amount of BPA to water only, and addition of NaCl to lipid containing water further decreased BPA concentration. The result indicates that BPA could be degraded by lipoperoxides formed by auto-oxidation of lipid, and NaCl plays an important role in BPA degradation. In the presence of ROS, BPA recovery was the lowest in water and addition of EtOH increased in both BPA recovery and TBA value, suggesting that EtOH could play a role as scavenger of ROS on the oxidative BPA degradation. Furthermore, the higher the concentration of lipid and/or NaCl, the lower the BPA recovery and TBA value. Physiologically and environmentally important concentrations of NaCl could enhance oxidative degradation of BPA in the presence of ROS.
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In this study, (1) change in the concentration of bisphenol A (BPA) leached from polycarbonate (PC) tube to control water (BPA free), seawater and river water at 20 and 37 degrees C as a function of time, (2) the fate of BPA caused by addition of H(2)O(2) and Fe(3+) to seawater containing BPA leached from PC tube were assessed. BPA leached from PC tube to all water samples increased with the ascendant of temperature and with the passage of time. The BPA leaching velocity in seawater was the fastest in three samples (11 ng/day for seawater, 4.8 ng/day for river water 0.8 ng/day for control water at 37 degrees C).BPA leaching velocity from PC tube was significantly high at pH 8 (50 mM Na(2)HPO(4)) and increased dose-dependently. There was no difference in the velocity of BPA among the 50 mM phosphate-buffers at pH 6.5, 7.0 and 7.5. BPA was leached three times higher by addition of Na(+) than K(+). However, the higher the K(+) concentration, the larger the BPA leached from PC tube. Na(+) mixed with PO(4)(-) was effective on BPA leaching from PC tube, but not with SO(4)(-) or Cl(-). The results suggested that BPA leaching from PC tube would be attributed to the concentration of bibasic phosphate such as Na(2)HPO(4) and K(2)HPO(4) in water samples. BPA was degraded in both control water and seawater in the presence of radical oxygen species, but the degradation rate was lower in seawater than in control water, suggesting that anti-oxidative system exists in seawater. Neo-synthesized substance in both control water and seawater in the presence of reactive oxygen species was identified as BPA-quinone by LC-MS.
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The plasma and urine levels of 19 free amino acids as determined microbiologically in fasting, healthy, young males are reported.