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Diethyl phthalate (DEP)

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The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Toxic organic micro-pollutants removal mechanisms in long-term operated membrane bioreactor treating municipal solid waste leachate

Authors: Boonyaroj, V; Chiemchaisri, C; Chiemchaisri, W; Theepharaksapan, S; Yamamoto, K (2012) Bioresource Technology 113:174-180. HERO ID: 1249543

[Less] The performance of two-stage membrane bioreactor (MBR) in term of toxic organic micro-pollutants removal . . . [More] The performance of two-stage membrane bioreactor (MBR) in term of toxic organic micro-pollutants removal was continuously monitored for 300 days under long sludge age condition. The phenolic compounds and phthalic acid esters (PAEs) in landfill leachate and treated water from MBR unit were quantified by solid phase extraction and gas chromatography-mass spectrometry. Priority pollutants in landfill leachate were phenolics and their degradation products i.e. 4-methyl-2,6-di-tert-butylphenol, bisphenol A at higher concentrations above 100 μg/l, PAEs i.e. dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, di-n-octyl phthalate, and di (2-ethylhexyl) phthalate. It was found that MBR could remove phenolic compounds and PAEs by 77-96%. Biodegradation and adsorption mechanisms were responsible for their removals in MBR. Additionally, the retention of compounds during filtration through the fouled membrane was also found significant. This research shows that the removal of organic micro-pollutants in landfill leachate was improved under higher biomass concentration and longer sludge age conditions.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Antiandrogenic activity of phthalate mixtures: validity of concentration addition

Authors: Christen, V; Crettaz, P; Oberli-Schrämmli, A; Fent, K (2012) Toxicology and Applied Pharmacology 259:169-176. HERO ID: 1249821

[Less] Phthalates and bisphenol A have very widespread use leading to significant exposure of humans. They . . . [More] Phthalates and bisphenol A have very widespread use leading to significant exposure of humans. They are suspected to interfere with the endocrine system, including the androgen, estrogen and the thyroid hormone system. Here we analyzed the antiandrogenic activity of six binary, and one ternary mixture of phthalates exhibiting complete antiandrogenic dose-response curves, and binary mixtures of phthalates and bisphenol A at equi-effective concentrations of EC(10), EC(25) and EC(50) in MDA-kb2 cells. Mixture activity followed the concentration addition (CA) model with a tendency to synergism at high and antagonism at low concentrations. Isoboles and the toxic unit approach (TUA) confirmed the additive to synergistic activity of the binary mixtures BBP+DBP, DBP+DEP and DEP+BPA at high concentrations. Both methods indicate a tendency to antagonism for the EC(10) mixtures BBP+DBP, BBP+DEP and DBP+DEP, and the EC(25) mixture of DBP+BPA. A ternary mixture revealed synergism at the EC(50), and weak antagonistic activity at the EC(25) level by the TUA. A mixture of five phthalates representing a human urine composition and reflecting exposure to corresponding parent compounds showed no antiandrogenic activity. Our study demonstrates that CA is an appropriate concept to account for mixture effects of antiandrogenic phthalates and bisphenol A. The interaction indicates a departure from additivity to antagonism at low concentrations, probably due to interaction with the androgen receptor and/or cofactors. This study emphasizes that a risk assessment of phthalates should account for mixture effects by applying the CA concept.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Comparison of different wastewater treatments for removal of selected endocrine-disruptors from paper mill wastewaters

Authors: Balabanic, D; Hermosilla, D; Merayo, N; Klemencic, AK; Blanco, A (2012) Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances & Environmental Engineering 47:1350-1363. HERO ID: 1322111

[Less] There is increasing concern about chemical pollutants that have the ability to mimic hormones, the so-called . . . [More] There is increasing concern about chemical pollutants that have the ability to mimic hormones, the so-called endocrine-disrupting compounds (EDCs). One of the main reasons for concern is the possible effect of EDCs on human health. EDCs may be released into the environment in different ways, and one of the most significant sources is industrial wastewater. The main objective of this research was to evaluate the treatment performance of different wastewater treatment procedures (biological treatment, filtration, advanced oxidation processes) for the reduction of chemical oxygen demand and seven selected EDCs (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, bisphenol A and nonylphenol) from wastewaters from a mill producing 100 % recycled paper. Two pilot plants were running in parallel and the following treatments were compared: (i) anaerobic biological treatment followed by aerobic biological treatment, ultrafiltration and reverse osmosis (RO), and (ii) anaerobic biological treatment followed by membrane bioreactor and RO. Moreover, at lab-scale, four different advanced oxidation processes (Fenton reaction, photo-Fenton reaction, photocatalysis with TiO(2), and ozonation) were applied. The results indicated that the concentrations of selected EDCs from paper mill wastewaters were effectively reduced (100 %) by both combinations of pilot plants and photo-Fenton oxidation (98 %), while Fenton process, photocatalysis with TiO(2) and ozonation were less effective (70 % to 90 %, respectively).

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Comparison and understanding of the different simulated sunlight photocatalytic activity between the saturated and monovacant Keggin unit functionalized titania materials

Authors: Ma, F; Shi, T; Gao, Jie; Chen, L; Guo, Wan; Guo, Y; Wang, S (2012) HERO ID: 1322149

[Less] The saturated and monovacant Keggin unit functionalized titania materials, H3PW12O40/TiO2 and K7PW11O39/TiO2, . . . [More] The saturated and monovacant Keggin unit functionalized titania materials, H3PW12O40/TiO2 and K7PW11O39/TiO2, were prepared by one step sol-gel co- condensation followed by solvothermal treatment. The structure, optical absorption properties, morphology, and porosity of the materials were well characterized. Subsequently, their simulated sunlight photocatalytic activity was evaluated by the degradation and mineralization of dye rhodamine B (RB) and endocrine-disrupting chemical diethyl phthalate (DEP). Special attention was paid to provide direct evidences for the explanation of the different photoexcited electron-hole pair separation rates of the H3PW12O40/TiO2, K7PW11O39/TiO2, and pure TiO2 by the photoelectrochemical experiment: simultaneously, the target active species yielded in the K7PW11O39/TiO2- and H3PW12O40/TiO2-catalyzed DEP degradation systems were also investigated by the free radical and hole scavenging experiment. Accordingly, reasons for the photocatalytic activity difference between the K7PW11O39/TiO2 and H3PW12O40/TiO2 as well as pure TiO2 were revealed. (C) 2012 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Preparation and characterization of molecularly imprinted polymer for di(2-ethylhexyl) phthalate: Application to sample clean-up prior to gas chromatographic determination

Authors: Shaikh, H; Memon, N; Khan, H; Bhanger, MI; Nizamani, SM (2012) Journal of Chromatography A 1247:125-133. HERO ID: 1322167

[Less] The molecularly imprinted polymer (MIP) selective for di(2-ethylhexyl) phthalate (DEHP) an environmental . . . [More] The molecularly imprinted polymer (MIP) selective for di(2-ethylhexyl) phthalate (DEHP) an environmental endocrine disruptor was prepared by suspension polymerization using methacrylamide as functional monomer and N,N'-methylene-bis-acrylamide as cross-linker. The imprinted polymer was employed for solid-phase extraction of DEHP from water samples of environmental importance and characterized by FT-IR and SEM. The adsorption properties of the imprinted polymer were demonstrated by equilibrium rebinding experiments, Pseudo-second-order kinetic model, Sips isotherm and Scatchard analysis. The reusability of MIP was checked for at least six repeated batch adsorption cycles and the results showed almost no deterioration in the adsorption capacity. The competitive recognition studies were performed with DEHP and structurally similar compounds; dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP). The imprinting factor (IF) of DEHP was found to be 12.86 which was much higher than the imprinting factors (IF) of other phthalates. A method constituted by molecularly imprinted solid-phase extraction (MISPE) with GC-FID was developed for DEHP analysis in water samples under very simple conditions. Sample loading and desorption conditions were also optimized. The MISPE method's linearity ranged from 0.035 to 3.0 μg ml⁻¹ with r² = 0.9998. Intra-assay, interassay precision and accuracy ranged from 0.0168% to 1.017%, 1.130% to 4.799% and 94.98% to 99.35%, respectively. The LOD and LOQ were found to be 0.011 and 0.035 μg ml⁻¹, respectively. Synthesized MIP was employed in MISPE for cleaning up the spiked river water samples prior to gas chromatographic analysis. The river samples were found to contain DEHP in the range of 1.4 × 10⁻³ to 0.349 μg ml⁻¹.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Immobilization of cholesterol esterase in mesoporous silica materials and its hydrolytic activity toward diethyl phthalate

Authors: Orita, T; Tomita, M; Saito, T; Nishida, N; Kato, K (2012) HERO ID: 1322266

[Less] Cholesterol esterase (CE, cholesteryl ester hydrolase, EC 3.1.1.13) from porcine pancreas (molecular . . . [More] Cholesterol esterase (CE, cholesteryl ester hydrolase, EC 3.1.1.13) from porcine pancreas (molecular weight 400-500 kDa) exhibits hydrolytic activity toward various toxic organic phthalate esters. CE was confined in the nanospace (diameter 3-30 nm) of five types of mesoporous silica (MPS) that differ in structural properties such as pore diameter, pore volume, and particle morphology. These structural properties were characterized by transmission electron microscopy, small-angle X-ray diffraction, N-2 adsorption-desorption experiments, solid-state C-13 nuclear magnetic resonance (NMR), and solid-state Si-29 NMR. Catalytic activities of immobilized and free CE were evaluated by the hydrolysis of diethyl phthalate in phosphate buffer solutions containing an organic cosolvent. Optimal activity recovery was achieved when CE was immobilized in n-decane-functionalized MPS, which had a large pore size (22.5 nm). The immobilization also protected against effects of temperature within the range 30 degrees C-60 degrees C; CE immobilized in n-decyl-functionalized MPS exhibited better thermal stability than in non-functionalized MPS or free CE Moreover, it retained approximately 60% of its catalytic activity even after six catalytic cycles. (c) 2012 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Effects of nitrate on the advanced UV photolysis of di(2-ethylhexyl) phthalate degradation in aqueous solution

Authors: Park, CG; Kim, JC (2012) Desalination and Water Treatment 47:163-170. HERO ID: 1322267

[Less] One of the objectives of this study was to delineate the effect of nitrate on the oxidation of di . . . [More] One of the objectives of this study was to delineate the effect of nitrate on the oxidation of di (2-ethylhexyl) phthalate (DEHP) by conducting bench- scale UV/H2O2 operations under a variety of UV doses and initial concentrations of H2O2 and NO3 --N. Also, this study evaluated the two processes, UV alone and UV/H2O2, for DEHP oxidation. DEHP separation and quantification were performed using liquid chromatography-electrospray ionization tandem mass spectrometry system (LC-ESI-MS/MS). It was found that the UV photolysis of H2O2 is a more effective method of DEHP oxidation than the direct UV photolysis. It was observed that the DEHP oxidation efficiency of about 85.0% or higher could be achieved at a UV dose of 800 mJ/cm(2) with an initial H2O2 concentration of more than 30mg/L in the absence of nitrate. Nitrate hindered the DEHP oxidation by acting as (OH)-O-center dot scavengers. The adverse effect by nitrate in the UV/H2O2 process was significantly greater than that in the UV oxidation-alone, and its oxidation was almost reduced to half by nitrate under some operating condition. However, it is noted that the DEHP oxidation efficiency of more than 70% could be expected at a UV dose of 600 mJ/cm(2) with an initial H2O2 concentration of 50mg/L while considering the nitrate scavenging effect.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Identification of phthalates in medications and dietary supplement formulations in the United States and Canada

Authors: Kelley, KE; Hernandez-Diaz, S; Chaplin, EL; Hauser, R; Mitchell, AA (2012) Environmental Health Perspectives 120:379-384. HERO ID: 5509166

[Less] Background: In animal studies, some ortho-phthalates, including di(2-ethylhexyl) phthalate (DEHP) and . . . [More] Background: In animal studies, some ortho-phthalates, including di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP), have been shown to be reproductive and developmental toxicants. Human studies show widespread population exposure to background levels of phthalates. Limited evidence suggests that particularly high exposure levels may result from orally ingested medicinal products containing phthalates as excipients (inactive ingredients). Objective: In this study we aimed to identify and describe the scope of prescription (RX) and nonprescription (over-the-counter; OTC) medicinal products and dietary supplements marketed in the United States and Canada since 1995 that include phthalates as excipients. Methods: We used lists of modified-release drug products to identify potential drug products. Inclusion of phthalates was verified using available electronic databases, print references, published package inserts, product packages, and direct communication from manufacturers. Additional products were identified using Internet searches utilizing keywords for phthalates. Results: Based on labeling information, 6 RX drug products included DBP as an excipient, and 45 specified the use of diethyl phthalate (DEP). Phthalate polymers with no known toxicity-hypromellose phthalate (HMP), cellulose acetate phthalate (CAP), and polyvinyl acetate phthalate (PVAP)-were included in 75 RX products. Three OTC drug and dietary supplement products listed DBP, 64 listed DEP, and > 90 indicated inclusion of polymers. Conclusions: Numerous RX and OTC drug products and supplements from a wide range of therapeutic categories may use DBP or DEP as excipients in oral dosage forms. The potential effects of human exposure to these phthalates through medications are unknown and warrant further investigation.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Plasticizers excreted in urine: indication of autologous blood transfusion in sports

Authors: Monfort, N; Ventura, R; Platen, P; Hinrichs, T; Brixius, K; Schänzer, W; Thevis, M; Geyer, H; Segura, J (2012) Transfusion 52:647-657. HERO ID: 787909

[Less] BACKGROUND: Misuse of autologous blood transfusions in sports remains undetectable. The metabolites . . . [More] BACKGROUND: Misuse of autologous blood transfusions in sports remains undetectable. The metabolites of the plasticizer di-(2-ethylhexyl)phthalate (DEHP) were recently proposed as markers of blood transfusion, based on high urinary concentrations of these compounds observed in patients subjected to blood transfusion. This study evaluates DEHP metabolites in urine for detecting autologous blood transfusion. STUDY DESIGN AND METHODS: One blood bag was drawn from moderately trained subjects and the red blood cells (RBCs) were reinfused after different storage periods. Group 1 (12 subjects) was reinfused after 14 days, and Group 2 (13 subjects), after 28 days of storage. Urine samples were collected before and after reinfusion for determination of the concentrations of three DEHP metabolites, mono-(2-ethylhexyl)phthalate, mono-(2-ethyl-5-hydroxyhexyl)phthalate, and mono-(2-ethyl-5-oxohexyl)phthalate. RESULTS: Concentrations of DEHP metabolites on the days before reinfusion were in agreement with those described after common environmental exposure. A few hours after the reinfusion a significant increase was observed for all metabolites in all volunteers. Concentrations 1 day later were still higher (p < 0.05) than before reinfusion. Variations in urine dilution supported normalization by specific gravity. Concentrations of DEHP metabolites tended to be higher after longer storage times of RBCs. CONCLUSION: Autologous transfusion with RBCs stored in plastic bags provokes an acute increase in the urinary concentrations of DEHP metabolites, allowing the detection of this doping malpractice. The window of detection is approximately 2 days. The method might be applied to urine samples submitted for antidoping testing.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Interpreting variability in population biomonitoring data: Role of elimination kinetics

Authors: Aylward, LL; Kirman, CR; Adgate, JL; Mckenzie, LM; Hays, SM (2012) Journal of Exposure Science and Environmental Epidemiology 22:398-408. HERO ID: 1248938

[Less] Biomarker concentrations in spot samples of blood and urine are implicitly interpreted as direct surrogates . . . [More] Biomarker concentrations in spot samples of blood and urine are implicitly interpreted as direct surrogates for long-term exposure magnitude in a variety of contexts including (1) epidemiological studies of potential health outcomes associated with general population chemical exposure, and (2) cross-sectional population biomonitoring studies. However, numerous factors in addition to exposure magnitude influence biomarker concentrations in spot samples, including temporal variation in spot samples because of elimination kinetics. The influence of half-life of elimination relative to exposure interval is examined here using simple first-order pharmacokinetic simulations of urinary concentrations in spot samples collected at random times relative to exposure events. Repeated exposures were modeled for each individual in the simulation with exposure amounts drawn from lognormal distributions with varying geometric standard deviations. Relative variation in predicted spot sample concentrations was greater than the variation in underlying dose distributions when the half-life of elimination was shorter than the interval between exposures, with the degree of relative variation increasing as the ratio of half-life to exposure interval decreased. Results of the modeling agreed well with data from a serial urine collection data set from the Centers for Disease Control. Data from previous studies examining intra-class correlation coefficients for a range of chemicals relying upon repeated sampling support the importance of considering the half-life relative to exposure frequency in design and interpretation of studies using spot samples for exposure classification and exposure estimation. The modeling and data sets presented here provide tools that can assist in interpretation of variability in cross-sectional biomonitoring studies and in design of studies utilizing biomonitoring data as markers for exposure.