Endocrine disruptors bisphenols

FIG. 1 Molecular structures of the drugs examined in the delivery study the general anesthetics, alkanols (I), halothane (II), enflurane (III), isoflurane (IV), halogenated cyclobutane (V) the local anesthetics, dibucaine hydrochloride (VI), procaine hydrochloride (VII), tetracaine hydrochloride (VIII), lidocaine hydrochloride (IX), benzyl alcohol (X) the endocrine disruptor, bisphenol A (XI), and alkylbenzenes, benzene (XII), toluene (XIII), ethylbenzene (XIV), and propylbenzene (XV). 

V. LIPID BILAYER INTERFACES COUPLED WITH ENDOCRINE DISRUPTORS, BISPHENOL A, AND ALKYLBENZENES... 

As an example of suspected endocrine disruptors (EDs), studies of the estrogenic action of bisphenol A (BPA) have been in progress in medical, physiological, and biological fields. In this situation, physicochemical approaches are required to get the structural information of BPA trapped in biomembranes. Most recently, we have determined the site and the orientation of BPA trapped in phospholipid vesicles by NMR, using the HCS rule [47]. In particular, we have succeeded in monitoring the NMR spectral changes of phospholipid vesicles, which are induced by the BPA delivery. 

Fig. 14). The DNA-immobilized columns effectively accumulated more DNA-intercalating materials than the planar DNA films. The DNA-immobilized columns bound endocrine disruptors with a planar structure, such as dioxins, and benzo[a]pyrene. Bisphenol A and diethylstilbestrol, which lack a planar structure, did not bind to the DNA-coated columns. Table 1 shows the selective adsorptions of the insoluble DNA-based materials. 

Significant uncertainty exists in the current risk assessment of bisphenol A, which has led to the EU regulatory risk assessment conclusion that further risk data need to be collected, especially because it is a potential endocrine disruptor. Under the systems framework, recommendations would apply during the time necessary to collect further information on bisphenol A, thereby providing a... 

As noted in Box 6.3, although bisphenol A is a potential endocrine disruptor, exposure levels are not anticipated to exceed any DNEL when used as a substance or preparation when correct safety measures are used. Further information is needed to confirm this risk assessment conclusion and examine the likelihood that exposure exceeds DNEL when safety measures are not applied. 

Xenoestrogens, exhibiting a wide molecular diversity, are found in a number of cosmetic products, such as plasticizers, perfume fixatives, and solvents (e.g., dibutyl phthalate), industrial chemicals and pollutants such as insecticides (e.g., methoxychlor, DDT, and DDE), epoxy resins, and polycarbonate (e.g., bisphenol A), and herbicides (e.g., simazine). This group of chemicals has been classified as environmental endocrine disruptor compounds (EDCs), defined as exogenous agents that interfere with the synthesis, transport, binding, action, or elimination of natural hormones in the body that are responsible for the maintenance of homeostasis, reproduction, development, and/or behavior. A list of representative chemicals is shown in Table 1 based on commercial usage. 

Recently, the hazardous effects of endocrine disruptors (environmental hormones) such as bisphenol A and nonylphenol on the human body have been reported, and led to the initiation of many studies concerning the detection and structural determination of these compounds present in tiny amounts [57]. As one of the QSAR analyses of environmental hormones, the relationship between their biological activity and chemical hardness has been reported [16]. By applying these analytical methods, the molecular toxicity and estrogen-like activity of environmental hormones have been found... 

Toxicology Bisphenol A can be released during thermal decomposition of epoxides above 250 °C, which can cause photosensitisation of the skin. Bisphenol A is not genotoxic in vivo, however, weak oestrogenic effects are observed in vitro. Some endocrine disruptor effects in animals and human cancer cells can occur at low levels (2-5 ppb). It has been claimed that these effects lead to health problems, mainly in men, of a lowered sperm count and infertile sperm. 

Manganese-oxide materials have been reported as efficient oxidants for the degradation of endocrine disruptive chemicals such as estrone, 17jS-estradiol, bisphenol A and bisphenol F, among others. Xu et al. studied the oxidative removal of several endocrine disruptors from water using synthetic 5-Mn02 (surface area = 128 m g ) as well as the factors that influenced its... 

The epoxy liners in tin cans leach bisphenol A (BPA), an endocrine disruptor, into the food contents. Ingesting even low levels of BPA is a health concern. While BPA-free cans with no epoxy liners are available, they are about 15% more expensive compared to conventional cans. Despite this disadvantage, some canned-food manufacturers have switched to the BPA-free cans. 

Contamination of the environment and agricultural products with endocrine disruptors(EDs) including dioxins, industrial chemicals and certain pesticide residues is a serious problem. These chemicals were found in the environment and agricultural products at nano-level concentrations, and are suspected of affecting ecosystems and human health. The Ministry of the Environment of Japan surveyed contamination of EDs in rivers, showing that bisphenol A, 176-estradiol and nonylphenol were detected in 50.3%, 40.4% and 31.0% of the water samples, respectively(Table 1). 

Dental amalgam, consisting of mercury alloyed with another element, is still approved for use in most countries, but conflicting views have been expressed over the use of mercury as filling material. Some dentists are still recommending the use of dental amalgam with mercury because of its durability, ease of use, and low cost compared to resin composites (for which concerns have been raised due to the presence of plastic chemicals such as Bisphenol A, well known for its endocrine disruptor effects) and dental porcelain. However, it is believed that leaching of mercury into the mouth and consequential health effects related to mercury toxicity (such as risk of impairment in the central nervous system function, kidney function, immune system, and fetal development) are associated with mercury exposure. 

Fullerene-C-60 was immobilized on glassy carbon by evaporation of a CH2CI2 solution. The adsorbed fullerene was cycled in 1 M NaOH for its reduction and the electrode was utilized for bisphenol quantification in wastewater. The detection limit was determined as 3.7 x 10 mol L . The association of fullerenes and MWCNT was explored for the quantification of the endocrine disruptor vinclozolin in wastewater. A glassy carbon electrode was polished and a solution containing both carbon forms (MWCNT C-60 = 2 1) were cast on the electrode that was dried at air. This electrode was applied for vinclozolin in optimized conditions, attaining a detection limit of 9.1 x 10 mol This sensor was successfully applied to... 

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