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Antonia M Calafat - One of the best experts on this subject based on the ideXlab platform.
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correlates of exposure to phenols parabens and Triclocarban in the study of environment lifestyle and fibroids
Journal of Exposure Science and Environmental Epidemiology, 2020Co-Authors: Traci N Bethea, Xiaoyun Ye, Antonia M Calafat, Amelia K Wesselink, Jennifer Weuve, Michael D Mcclean, Russ Hauser, Paige L Williams, Donna D Baird, Lauren A WiseAbstract:We performed a cross-sectional analysis to identify correlates of urinary concentrations of seven phenols (bisphenols A, F, and S; 2,4-dichlorophenol; 2,5-dichlorophenol; benzophenone-3; triclosan), Triclocarban, and four parabens (butyl, ethyl, methyl, and propyl). We analyzed baseline data from 766 participants in the Study of Environment, Lifestyle, and Fibroids, a prospective cohort study of 1693 Black women aged 23–34 years residing in Detroit, Michigan (2010–2012). We collected data on demographic, behavioral, and anthropometric factors via telephone interviews, clinic visits, and self-administered questionnaires. For each biomarker, we used linear regression models to estimate mean differences in log-transformed, creatinine-corrected concentrations across factors of interest. Each biomarker was detected in >50% of participants. Median creatinine-corrected concentrations were the highest for methyl paraben (116.8 μg/g creatinine), propyl paraben (16.8 μg/g creatinine), and benzophenone-3 (13.4 μg/g creatinine). Variables most strongly associated with biomarker concentrations included season of urine collection, education, and body mass index (BMI). BMI was positively associated with bisphenol A and S and Triclocarban concentrations and inversely associated with butyl and methyl paraben concentrations. In this cohort of Black women, exposure to phenols, parabens, and Triclocarban was prevalent and several factors were associated with biomarker concentrations.
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a repeated measures study of phenol paraben and Triclocarban urinary biomarkers and circulating maternal hormones during gestation in the puerto rico protect cohort
Environmental Health, 2019Co-Authors: Amira Aker, Antonia M Calafat, Zaira Rosario, Akram N Alshawabkeh, Jose F Cordero, Bhramar Mukherjee, Kelly K Ferguson, John D MeekerAbstract:Prenatal exposure to some phenols and parabens has been associated with adverse birth outcomes. Hormones may play an intermediate role between phenols and adverse outcomes. We examined the associations of phenol and paraben exposures with maternal reproductive and thyroid hormones in 602 pregnant women in Puerto Rico. Urinary Triclocarban, phenol and paraben biomarkers, and serum hormones (estriol, progesterone, testosterone, sex-hormone-binding globulin (SHBG), corticotropin-releasing hormone (CRH), total triiodothyronine (T3), total thyroxine (T4), free thyroxine (FT4) and thyroid-stimulating hormone (TSH)) were measured at two visits during pregnancy. Linear mixed models with a random intercept were constructed to examine the associations between hormones and urinary biomarkers. Results were additionally stratified by study visit. Results were transformed to hormone percent changes for an inter-quartile-range difference in exposure biomarker concentrations (%Δ). Bisphenol-S was associated with a decrease in CRH [(%Δ -11.35; 95% CI: -18.71, − 3.33), and bisphenol-F was associated with an increase in FT4 (%Δ: 2.76; 95% CI: 0.29, 5.22). Butyl-, methyl- and propylparaben were associated with decreases in SHBG [(%Δ: -5.27; 95% CI: -9.4, − 1.14); (%Δ: -3.53; 95% CI: -7.37, 0.31); (%Δ: -3.74; 95% CI: -7.76, 0.27)]. Triclocarban was positively associated with T3 (%Δ: 4.08; 95% CI: 1.18, 6.98) and T3/T4 ratio (%Δ: 4.67; 95% CI: -1.37, 6.65), and suggestively negatively associated with TSH (%Δ: -10.12; 95% CI: -19.47, 0.32). There was evidence of susceptible windows of vulnerability for some associations. At 24–28 weeks gestation, there was a positive association between 2,4-dichlorophenol and CRH (%Δ: 9.66; 95% CI: 0.67, 19.45) and between triclosan and estriol (%Δ: 13.17; 95% CI: 2.34, 25.2); and a negative association between Triclocarban and SHBG (%Δ: -9.71; 95% CI:-19.1, − 0.27) and between bisphenol A and testosterone (%Δ: -17.37; 95% CI: -26.7, − 6.87). Phenols and parabens are associated with hormone levels during pregnancy. Further studies are required to substantiate these findings.
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elevated concentrations of urinary Triclocarban phenol and paraben among pregnant women in northern puerto rico predictors and trends
Environment International, 2018Co-Authors: Pahriya Ashrap, Xiaoyun Ye, Antonia M Calafat, Deborah J Watkins, Zaira Rosario, Phil Brown, Carmen M Velezvega, Akram N Alshawabkeh, Jose F Cordero, John D MeekerAbstract:Abstract Background Understanding important sources and pathways of exposure to common chemicals known or suspected to impact human health is critical to eliminate or reduce the exposure. This is particularly important in areas such as Puerto Rico, where residents have higher exposures to numerous chemicals, as well as higher rates of many adverse health outcomes, compared to the mainland US. Objective The aim of this study was to assess distributions, time trends, and predictors of urinary Triclocarban, phenol, and paraben biomarkers measured at multiple times during pregnancy among women living in Northern Puerto Rico. Methods We recruited 1003 pregnant women between years 2010 and 2016 from prenatal clinics and collected urine samples and questionnaire data on personal care product use at up to three separate visits, between 16 and 28 weeks gestation. Urine samples were analyzed for Triclocarban, seven phenols and four parabens: 2,4-dichlorophenol, 2,5-dichlorophenol, benzophenone-3, bisphenol A (BPA), bisphenol S (BPS), bisphenol F, triclosan, butylparaben, ethylparaben, methylparaben, and propylparaben. Results Detectable Triclocarban, phenol and paraben concentrations among pregnant women were prevalent and tended to be higher than levels measured in women of reproductive age from the general US population, especially Triclocarban, which had a median concentration 37 times higher in Puerto Rico participants (2.6 vs 0.07 ng/mL). A decreasing temporal trend was statistically significant for urine concentrations of BPA during the study period, while the BPA substitute BPS showed an increasing temporal trend. Significant and positive associations were found between biomarker concentrations with the products use in the past 48-h (soap, sunscreen, lotion, cosmetics). There was an increasing trend of Triclocarban/triclosan urinary concentrations with increased concentrations of Triclocarban/triclosan listed as the active ingredient in the bar soap/liquid soap products reported being used. Conclusion Our results suggest several potential exposure sources to Triclocarban, phenols, and parabens in this population and may help inform targeted approaches to reduce exposure.
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urinary concentrations of the antibacterial agent Triclocarban in united states residents 2013 2014 national health and nutrition examination survey
Environmental Science & Technology, 2016Co-Authors: Xiaoyun Ye, Leeyang Wong, Prabha Dwivedi, Xiaoliu Zhou, Antonia M CalafatAbstract:Triclocarban is widely used as an antibacterial agent in personal care products, and the potential for human exposure exists. We present here the first nationally representative assessment of exposure to Triclocarban among Americans ≥6 years of age who participated in the 2013–2014 National Health and Nutrition Examination Survey. We detected Triclocarban at concentrations above 0.1 μg/L in 36.9% of 2686 urine samples examined. Triclocarban was detected more frequently in adolescents and adults than in children, and in non-Hispanic black compared to other ethnic groups. In univariate analysis, log-creatinine, sex, age, race, and body surface area (BSA) were significantly associated with the likelihood of having Triclocarban concentrations above the 95th percentile. In multiple regression models, persons with BSA at or above the median (≥1.86 m2) were 2.43 times more likely than others, and non-Hispanic black and non-Hispanic white were 3.71 times and 2.23 times more likely than “all Hispanic,” respectivel...
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Urinary Concentrations of the Antibacterial Agent Triclocarban in United States Residents: 2013–2014 National Health and Nutrition Examination Survey
Environmental Science & Technology, 2016Co-Authors: Xiaoyun Ye, Leeyang Wong, Prabha Dwivedi, Xiaoliu Zhou, Antonia M CalafatAbstract:Triclocarban is widely used as an antibacterial agent in personal care products, and the potential for human exposure exists. We present here the first nationally representative assessment of exposure to Triclocarban among Americans ≥6 years of age who participated in the 2013–2014 National Health and Nutrition Examination Survey. We detected Triclocarban at concentrations above 0.1 μg/L in 36.9% of 2686 urine samples examined. Triclocarban was detected more frequently in adolescents and adults than in children, and in non-Hispanic black compared to other ethnic groups. In univariate analysis, log-creatinine, sex, age, race, and body surface area (BSA) were significantly associated with the likelihood of having Triclocarban concentrations above the 95th percentile. In multiple regression models, persons with BSA at or above the median (≥1.86 m2) were 2.43 times more likely than others, and non-Hispanic black and non-Hispanic white were 3.71 times and 2.23 times more likely than “all Hispanic,” respectivel...
Rolf U Halden - One of the best experts on this subject based on the ideXlab platform.
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assessment of human exposure to Triclocarban triclosan and five parabens in u s indoor dust using dispersive solid phase extraction followed by liquid chromatography tandem mass spectrometry
Journal of Hazardous Materials, 2018Co-Authors: Jing Chen, Erica M Hartmann, Jeff Kline, Kevin Van Den Wymelenberg, Rolf U HaldenAbstract:Abstract Antimicrobials in indoor dust pose concerns due to their endocrine disrupting activities and potential promotion of antibiotic resistance. We adopted dispersive solid phase extraction (d-SPE) and liquid chromatography-tandem mass spectrometry (LC–MS/MS) to quantify antimicrobials in dust. The method showed favorable linearity (R2 >0.99), recovery (83–115%), and method detection limits (1.2–5.6 ng/g, dry weight). All seven analytes were found at median concentrations in ng/g in each of the 80 U.S. dust samples collected from athletic facilities and residential homes: methyl paraben (1920) > propyl paraben (965) > triclosan (390) > Triclocarban (270) > ethyl paraben (195) > butyl paraben (80) > benzyl paraben (6). Triclosan levels in dust from athletic facilities were significantly higher than those in private homes (p
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activated carbon as a means of limiting bioaccumulation of organochlorine pesticides triclosan Triclocarban and fipronil from sediments rich in organic matter
Chemosphere, 2018Co-Authors: Rolf U Halden, Viet D Dang, Kevin J Kroll, Samuel D Supowit, Nancy D DenslowAbstract:Abstract Addition of activated carbon to contaminated sediment is an established means of remediation but its applicability to sediments high in organic carbon is presently unknown. We evaluated the effects of adding either granular activated carbon (GAC) or pelletized fine-grained activated carbon (PfAC, containing ∼ 50% AC) to contaminated sediments from Lake Apopka featuring a very high total organic carbon content (∼39% w/w dry). Sediments showing background levels of legacy pesticides were spiked with a mixture of 5 chemicals (p,p′-DDE, dieldrin, triclosan, Triclocarban, and fipronil) to a nominal concentration of 2 μg/g sediment for each chemical. Following incubation of spiked sediments with the addition of activated carbon for 30 days, we assessed the success on limiting bioaccumulation using Lumbriculus variegatus (blackworm). In contaminant-spiked sediments amended with PfAC, blackworm body burdens of triclosan, Triclocarban, and fipronil decreased by >50% and those of p,p′-DDE and dieldrin decreased by
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the florence statement on triclosan and Triclocarban
Environmental Health Perspectives, 2017Co-Authors: Rolf U Halden, Avery E Lindeman, Allison E Aiello, David Q Andrews, William A Arnold, Patricia A Fair, Rebecca Fuoco, Laura A Geer, Paula I Johnson, Rainer LohmannAbstract:The Florence Statement on Triclosan and Triclocarban documents a consensus of more than 200 scientists and medical professionals on the hazards of and lack of demonstrated benefit from common uses of triclosan and Triclocarban. These chemicals may be used in thousands of personal care and consumer products as well as in building materials. Based on extensive peer-reviewed research, this statement concludes that triclosan and Triclocarban are environmentally persistent endocrine disruptors that bioaccumulate in and are toxic to aquatic and other organisms. Evidence of other hazards to humans and ecosystems from triclosan and Triclocarban is presented along with recommendations intended to prevent future harm from triclosan, Triclocarban, and antimicrobial substances with similar properties and effects. Because antimicrobials can have unintended adverse health and environmental impacts, they should only be used when they provide an evidence-based health benefit. Greater transparency is needed in product formulations, and before an antimicrobial is incorporated into a product, the long-term health and ecological impacts should be evaluated. https://doi.org/10.1289/EHP1788.
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The Florence Statement on Triclosan and Triclocarban
Environmental Health Perspectives, 2017Co-Authors: Rolf U Halden, Avery E Lindeman, Allison E Aiello, David Q Andrews, William A Arnold, Patricia A Fair, Rebecca Fuoco, Laura A Geer, Paula I Johnson, Rainer LohmannAbstract:Summary: The Florence Statement on Triclosan and Triclocarban documents a consensus of more than 200 scientists and medical professionals on the hazards of and lack of demonstrated benefit from com...
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lessons learned from probing for impacts of triclosan and Triclocarban on human microbiomes
mSphere, 2016Co-Authors: Rolf U HaldenAbstract:ABSTRACT Despite increasing interest in the effects of triclosan and Triclocarban on human biology, current knowledge is still limited on the impact of these additives to antimicrobial personal care products on the human microbiome. A carefully designed recent study published in mSphere by Poole and colleagues [A. C. Poole et al., mSphere 1(3):e00056-15, 2016, http://dx.doi.org/10.1128/mSphere.00056-15] highlights both the power of novel methodologies for microbiome elucidation and the longstanding challenge of employing small-cohort studies to inform risk assessment for chemicals of ubiquitous use in modern society.
Xikui Wang - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous Determination of Triclocarban and Triclosan in Environmental Water by Using SPE Combined with HPLC-ESI-MS
Advanced Materials Research, 2012Co-Authors: Chun Liang Yi, Xikui WangAbstract:A sensitive method for the simultaneous determination of TCC and TCS in water, which involves enrichment with SPE and detection with HPLC-ESI-MS, was developed. The influence of the operational parameters,such as eluan, the acidity of the sample, were investigated and optimized. Under the optimum conditions, the limits of detection were 1.0 ng L-1and 2.5 ng L-1 for TCC and TCS, respectively. The method was successfully applied to the analysis of Triclocarban and triclosan in real environmental water samples, including river water, lake water and tap-water. The spiked recoveries of TCC and TCS in these samples were achieved in the range of 89.5%–97.5%.
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temperature controlled ionic liquid dispersive liquid phase microextraction for the sensitive determination of triclosan and Triclocarban in environmental water samples prior to hplc esi ms ms
IEEE Journal of Solid-state Circuits, 2010Co-Authors: Rusong Zhao, Xia Wang, Jinpeng Yuan, Shanshan Wang, Xikui WangAbstract:A novel dispersive liquid-phase microextraction method without dispersive solvents has been developed for the enrichment and sensitive determination of triclosan and Triclocarban in environmental water samples prior to HPLC-ESI-MS/MS. This method used only green solvent 1-hexyl-3-methylimidazolium hexafluorophosphate as extraction solvent and overcame the demerits of the use of toxic solvents and the instability of the suspending drop in single drop liquid-phase microextraction. Important factors that may influence the enrichment efficiencies, such as volume of ionic liquid, pH of solutions, extraction time, centrifuging time and temperature, were systematically investigated and optimized. Under optimum conditions, linearity of the method was observed in the range of 0.1-20 microg/L for Triclocarban and 0.5-100 microg/L for triclosan, respectively, with adequate correlation coefficients (R>0.9990). The proposed method has been found to have excellent detection sensitivity with LODs of 0.04 and 0.3 microg/L, and precisions of 4.7 and 6.0% (RSDs, n=5) for Triclocarban and triclosan, respectively. This method has been successfully applied to analyze real water samples and satisfactory results were achieved.
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trace determination of triclosan and Triclocarban in environmental water samples with ionic liquid dispersive liquid phase microextraction prior to hplc esi ms ms
Analytical and Bioanalytical Chemistry, 2010Co-Authors: Rusong Zhao, Xia Wang, Jinpeng Yuan, Shanshan Wang, Xikui WangAbstract:A novel and environmentally friendly microextraction method, termed ionic liquid dispersive liquid-phase microextraction (IL-DLPME), has been developed for rapid enrichment of triclosan and Triclocarban before analysis by high-performance liquid phase chromatography–electrospray tandem mass spectrometry (HPLC–ESI-MS–MS). Instead of using toxic organic solvents, an ionic liquid was used as a green extraction solvent. This also avoided the instability of the suspending drop in single-drop liquid-phase microextraction, and the heating and cooling step in temperature-controlled ionic liquid dispersive liquid phase microextraction. Factors that may affect the enrichment efficiency, for example volume of ionic liquid, type and volume of dispersive solvent, pH, extraction time, and NaCl content were investigated in detail and optimized. Under optimum conditions, linearity of the method was observed over the range 0.2–12 μg L−1 for Triclocarban and 1–60 μg L−1 for triclosan with correlation coefficients ranging from 0.9980 to 0.9990, respectively. The sensitivity of the proposed method was found to be excellent, with limits of detection in the range 0.040–0.58 μg L−1 and precision in the range 7.0–8.8% (RSD, n = 5). This method has been successfully used to analyze real environmental water samples and satisfactory results were achieved. Average recoveries of spiked compounds were in the range 70.0–103.5%. All these results indicated that the developed method would be a green method for rapid determination of triclosan and Triclocarban at trace levels in environmental water samples.
Xiaoyun Ye - One of the best experts on this subject based on the ideXlab platform.
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correlates of exposure to phenols parabens and Triclocarban in the study of environment lifestyle and fibroids
Journal of Exposure Science and Environmental Epidemiology, 2020Co-Authors: Traci N Bethea, Xiaoyun Ye, Antonia M Calafat, Amelia K Wesselink, Jennifer Weuve, Michael D Mcclean, Russ Hauser, Paige L Williams, Donna D Baird, Lauren A WiseAbstract:We performed a cross-sectional analysis to identify correlates of urinary concentrations of seven phenols (bisphenols A, F, and S; 2,4-dichlorophenol; 2,5-dichlorophenol; benzophenone-3; triclosan), Triclocarban, and four parabens (butyl, ethyl, methyl, and propyl). We analyzed baseline data from 766 participants in the Study of Environment, Lifestyle, and Fibroids, a prospective cohort study of 1693 Black women aged 23–34 years residing in Detroit, Michigan (2010–2012). We collected data on demographic, behavioral, and anthropometric factors via telephone interviews, clinic visits, and self-administered questionnaires. For each biomarker, we used linear regression models to estimate mean differences in log-transformed, creatinine-corrected concentrations across factors of interest. Each biomarker was detected in >50% of participants. Median creatinine-corrected concentrations were the highest for methyl paraben (116.8 μg/g creatinine), propyl paraben (16.8 μg/g creatinine), and benzophenone-3 (13.4 μg/g creatinine). Variables most strongly associated with biomarker concentrations included season of urine collection, education, and body mass index (BMI). BMI was positively associated with bisphenol A and S and Triclocarban concentrations and inversely associated with butyl and methyl paraben concentrations. In this cohort of Black women, exposure to phenols, parabens, and Triclocarban was prevalent and several factors were associated with biomarker concentrations.
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elevated concentrations of urinary Triclocarban phenol and paraben among pregnant women in northern puerto rico predictors and trends
Environment International, 2018Co-Authors: Pahriya Ashrap, Xiaoyun Ye, Antonia M Calafat, Deborah J Watkins, Zaira Rosario, Phil Brown, Carmen M Velezvega, Akram N Alshawabkeh, Jose F Cordero, John D MeekerAbstract:Abstract Background Understanding important sources and pathways of exposure to common chemicals known or suspected to impact human health is critical to eliminate or reduce the exposure. This is particularly important in areas such as Puerto Rico, where residents have higher exposures to numerous chemicals, as well as higher rates of many adverse health outcomes, compared to the mainland US. Objective The aim of this study was to assess distributions, time trends, and predictors of urinary Triclocarban, phenol, and paraben biomarkers measured at multiple times during pregnancy among women living in Northern Puerto Rico. Methods We recruited 1003 pregnant women between years 2010 and 2016 from prenatal clinics and collected urine samples and questionnaire data on personal care product use at up to three separate visits, between 16 and 28 weeks gestation. Urine samples were analyzed for Triclocarban, seven phenols and four parabens: 2,4-dichlorophenol, 2,5-dichlorophenol, benzophenone-3, bisphenol A (BPA), bisphenol S (BPS), bisphenol F, triclosan, butylparaben, ethylparaben, methylparaben, and propylparaben. Results Detectable Triclocarban, phenol and paraben concentrations among pregnant women were prevalent and tended to be higher than levels measured in women of reproductive age from the general US population, especially Triclocarban, which had a median concentration 37 times higher in Puerto Rico participants (2.6 vs 0.07 ng/mL). A decreasing temporal trend was statistically significant for urine concentrations of BPA during the study period, while the BPA substitute BPS showed an increasing temporal trend. Significant and positive associations were found between biomarker concentrations with the products use in the past 48-h (soap, sunscreen, lotion, cosmetics). There was an increasing trend of Triclocarban/triclosan urinary concentrations with increased concentrations of Triclocarban/triclosan listed as the active ingredient in the bar soap/liquid soap products reported being used. Conclusion Our results suggest several potential exposure sources to Triclocarban, phenols, and parabens in this population and may help inform targeted approaches to reduce exposure.
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urinary concentrations of the antibacterial agent Triclocarban in united states residents 2013 2014 national health and nutrition examination survey
Environmental Science & Technology, 2016Co-Authors: Xiaoyun Ye, Leeyang Wong, Prabha Dwivedi, Xiaoliu Zhou, Antonia M CalafatAbstract:Triclocarban is widely used as an antibacterial agent in personal care products, and the potential for human exposure exists. We present here the first nationally representative assessment of exposure to Triclocarban among Americans ≥6 years of age who participated in the 2013–2014 National Health and Nutrition Examination Survey. We detected Triclocarban at concentrations above 0.1 μg/L in 36.9% of 2686 urine samples examined. Triclocarban was detected more frequently in adolescents and adults than in children, and in non-Hispanic black compared to other ethnic groups. In univariate analysis, log-creatinine, sex, age, race, and body surface area (BSA) were significantly associated with the likelihood of having Triclocarban concentrations above the 95th percentile. In multiple regression models, persons with BSA at or above the median (≥1.86 m2) were 2.43 times more likely than others, and non-Hispanic black and non-Hispanic white were 3.71 times and 2.23 times more likely than “all Hispanic,” respectivel...
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Urinary Concentrations of the Antibacterial Agent Triclocarban in United States Residents: 2013–2014 National Health and Nutrition Examination Survey
Environmental Science & Technology, 2016Co-Authors: Xiaoyun Ye, Leeyang Wong, Prabha Dwivedi, Xiaoliu Zhou, Antonia M CalafatAbstract:Triclocarban is widely used as an antibacterial agent in personal care products, and the potential for human exposure exists. We present here the first nationally representative assessment of exposure to Triclocarban among Americans ≥6 years of age who participated in the 2013–2014 National Health and Nutrition Examination Survey. We detected Triclocarban at concentrations above 0.1 μg/L in 36.9% of 2686 urine samples examined. Triclocarban was detected more frequently in adolescents and adults than in children, and in non-Hispanic black compared to other ethnic groups. In univariate analysis, log-creatinine, sex, age, race, and body surface area (BSA) were significantly associated with the likelihood of having Triclocarban concentrations above the 95th percentile. In multiple regression models, persons with BSA at or above the median (≥1.86 m2) were 2.43 times more likely than others, and non-Hispanic black and non-Hispanic white were 3.71 times and 2.23 times more likely than “all Hispanic,” respectivel...
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biomarkers of exposure to Triclocarban in urine and serum
Toxicology, 2011Co-Authors: Xiaoyun Ye, Xiaoliu Zhou, Bruce D Hammock, Johnathan Furr, Earl L Gray, Antonia M CalafatAbstract:3,4,4'-Trichlorocarbanilide (Triclocarban, TCC) is widely used as an antimicrobial agent in a variety of consumer and personal care products. TCC is considered a potential endocrine disruptor, but its potential toxic effects in humans are still largely unknown. Because of its widespread uses, the potential for human exposure to TCC is high. In order to identify adequate exposure biomarkers of TCC, we investigated the metabolic profile of TCC in adult female Sprague Dawley rats after administering TCC once (500 mg/kg body weight) by oral gavage. Urine was collected 0-24 h before dosing, and 0-24 h and 24-48 h after dosing. Serum was collected at necropsy 48 h after dosing. We identified several metabolites of TCC in urine and serum by on-line solid phase extraction-high performance liquid chromatography-mass spectrometry. We unambiguously identified two major oxidative metabolites of TCC, 3'-hydroxy-TCC and 2'-hydroxy-TCC, by comparing their chromatographic behavior and mass spectral fragmentation patterns with those of authentic standards. By contrast, compared to these oxidative metabolites, we detected very low levels of TCC in the urine or serum. Taken together these data suggest that in rats, oxidation of TCC is a major metabolic pathway. We also measured TCC and its oxidative metabolites in 50 urine and 16 serum samples collected from adults in the United States. The results suggest differences in the metabolic profile of TCC in rats and in humans; oxidation appears to be a minor metabolic pathway in humans. Total (free plus conjugated) TCC could serve as a potential biomarker for human exposure to TCC.
Rusong Zhao - One of the best experts on this subject based on the ideXlab platform.
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temperature controlled ionic liquid dispersive liquid phase microextraction for the sensitive determination of triclosan and Triclocarban in environmental water samples prior to hplc esi ms ms
IEEE Journal of Solid-state Circuits, 2010Co-Authors: Rusong Zhao, Xia Wang, Jinpeng Yuan, Shanshan Wang, Xikui WangAbstract:A novel dispersive liquid-phase microextraction method without dispersive solvents has been developed for the enrichment and sensitive determination of triclosan and Triclocarban in environmental water samples prior to HPLC-ESI-MS/MS. This method used only green solvent 1-hexyl-3-methylimidazolium hexafluorophosphate as extraction solvent and overcame the demerits of the use of toxic solvents and the instability of the suspending drop in single drop liquid-phase microextraction. Important factors that may influence the enrichment efficiencies, such as volume of ionic liquid, pH of solutions, extraction time, centrifuging time and temperature, were systematically investigated and optimized. Under optimum conditions, linearity of the method was observed in the range of 0.1-20 microg/L for Triclocarban and 0.5-100 microg/L for triclosan, respectively, with adequate correlation coefficients (R>0.9990). The proposed method has been found to have excellent detection sensitivity with LODs of 0.04 and 0.3 microg/L, and precisions of 4.7 and 6.0% (RSDs, n=5) for Triclocarban and triclosan, respectively. This method has been successfully applied to analyze real water samples and satisfactory results were achieved.
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trace determination of triclosan and Triclocarban in environmental water samples with ionic liquid dispersive liquid phase microextraction prior to hplc esi ms ms
Analytical and Bioanalytical Chemistry, 2010Co-Authors: Rusong Zhao, Xia Wang, Jinpeng Yuan, Shanshan Wang, Xikui WangAbstract:A novel and environmentally friendly microextraction method, termed ionic liquid dispersive liquid-phase microextraction (IL-DLPME), has been developed for rapid enrichment of triclosan and Triclocarban before analysis by high-performance liquid phase chromatography–electrospray tandem mass spectrometry (HPLC–ESI-MS–MS). Instead of using toxic organic solvents, an ionic liquid was used as a green extraction solvent. This also avoided the instability of the suspending drop in single-drop liquid-phase microextraction, and the heating and cooling step in temperature-controlled ionic liquid dispersive liquid phase microextraction. Factors that may affect the enrichment efficiency, for example volume of ionic liquid, type and volume of dispersive solvent, pH, extraction time, and NaCl content were investigated in detail and optimized. Under optimum conditions, linearity of the method was observed over the range 0.2–12 μg L−1 for Triclocarban and 1–60 μg L−1 for triclosan with correlation coefficients ranging from 0.9980 to 0.9990, respectively. The sensitivity of the proposed method was found to be excellent, with limits of detection in the range 0.040–0.58 μg L−1 and precision in the range 7.0–8.8% (RSD, n = 5). This method has been successfully used to analyze real environmental water samples and satisfactory results were achieved. Average recoveries of spiked compounds were in the range 70.0–103.5%. All these results indicated that the developed method would be a green method for rapid determination of triclosan and Triclocarban at trace levels in environmental water samples.
