N-acyl ethanolamines (NAEs) are a class of lipids recently recognized as signaling molecules which are controlled, in part, by their degradation by fatty acid amide hydrolase (FAAH). On the basis of previous studies indicating increased NAE levels in a tobacco cell suspension-xylanase elicitor exposure system and the availability of FAAH mutants, overexpressor and knockout (OE and KO) genotypes in Arabidopsis thaliana, further roles of NAEs in A. thaliana plant defense was investigated. The commonly occurring urban antimicrobial contaminant triclosan (TCS) has been shown to suppress lipid signaling associated with plant defense responses. Thus, a second objective of this study was to determine if TCS exposure specifically interferes with NAE levels. No changes in steady state NAE profiles in A. thaliana-Pseudomonas syringae pv. syringae and A. thaliana-flagellin (bacterial peptide, flg22) challenge systems were seen despite evidence that defense responses were activated in these systems. There was a significant drop in enoyl-ACP reductase (ENR) enzyme activity, which catalyzes the last step in the fatty acid biosynthesis pathway in plants, on exposure of the seedlings to TCS at 10 ppm for 24 h and decreased reactive oxygen species (ROS) production due to flg22 in long term exposure of 0.1 ppm and short term exposure of 5 ppm. However, these responses were not accompanied by significant changes in steady state NAE profiles.

The presence of pharmaceuticals and personal care products (PPCPs) in the environment has become a matter of concern during the last decade. Increased production of PPCPs along with their increased use has led to release of these compounds in the environment via various routes. PPCPs includes large group of compounds including veterinary and human antibiotics, analgesics and anti-inflammatory drugs, psychiatric drugs, β-blockers, X-ray contrasts, and steroid hormones, etc. Many of the compounds used in PPCPs have been shown to possess adverse effects to living organisms and act as endocrine disrupting agents (ECDs). This dissertation includes the investigation of the occurrence of antibiotic compounds added to personal care product and the transformation of hormones used in pharmaceuticals such as contraceptives. The results obtained in this study can provide information on the fate and transformation of the studied compounds once released in the environment. An analytical method employing sonication extraction and HPLC-ESI-MS detection was developed. The developed method was used to detect antibiotic compounds triclosan (TCS) and triclocarban (TCC) in biosolids-applied soil and biosolids. Both TCS and TCC were detected at high concentrations in biosolids and at lower concentrations in biosolids-applied soil. TCS and TCC concentrations decreased in biosolids composts and in biosolids-applied soil collected at deeper depths. The developed method was able to provide efficient detection limits and reliable quantification of target compounds. A molecularly imprinted polymer (MIP) was synthesized to achieve efficient clean-up of TCS and TCC from biosolids-applied soil and biosolids samples using 4,4’- DBP-4-vp-EGDMA. The motivation behind this project was to be able to eliminate the use of expensive instruments such as LC-MS and employ easily available instruments such as LC-UV. The synthesized MIP was able to achieve efficient clean-up and allowed quantification and identification of TCS and TCC in a complex matrix. Transformation of hormones such as 17β-estradiol, estriol, ethynlestradiol, estrone and testosterone was studied by employing Fe (III)-saturated montmorillonite catalysts. The use of Fe (III) – saturated montmorillonite as a catalyst proved be to very efficient in transformation of the studied hormones. Complete removal of hormones was observed in aqueous environment. LC-UV was used for detection and quantification of hormones.

Le triclosan, un biocide aujourd’hui largement répandu dans l’environnement, peut engendrer des effets négatifs sur les organismes qui y sont exposés. Une infrastructure bleue, les marais filtrants, est proposée comme une solution appropriée pour mitiger les risques liés à ce contaminant. Cependant, les recherches sont toujours incomplètes quant aux impacts du triclosan sur l’état écologique et les performances de cette phytotechnologie. Mon projet de recherche a ainsi pour but d’établir les effets du triclosan en mésocosme de marais filtrants. Pour ce faire, des monocultures et polycultures de trois plantes indigènes au Canada ont été étudiées, en détaillant les impacts du triclosan sur l’efficacité du dispositif expérimental et sur la santé l’écosystème associé. Bien que les végétaux sélectionnés possèdent des taux d’enlèvement des polluants typiques (ammonium, nitrite, nitrate et orthophosphate) très variés, ainsi que des biomasses très divergentes, contrairement à d’autres études, le triclosan n’a pas eu d’impacts sur ces paramètres. Le biocide a toutefois affecté négativement l’Eutrochium maculatum au niveau physiomorphologique, mais Sporobolus michauxianus et Phragmites australis subsp. americanus présentent à l’inverse des signes de résilience. Le potentiel d’oxydo- réduction ainsi que la biomasse algale et bactérienne photosynthétique de l’effluent sont significativement réduits en présence du polluant. Le triclosan a également influencé le microbiote du substrat, des racines et de la rhizosphère, notamment en modifiant la structure des communautés bactériennes et en réduisant significativement la diversité alpha du substrat des monocultures. Cependant, les mésocosmes de polyculture exposés au triclosan semblent résistants, et l'analyse in vivo BIOLOGTM EcoPlate de la caractérisation des fonctions métaboliques des communautés a permis d'identifier la dégradation possible de molécule comparative au triclosan résiduel au sein des mésocosmes.Cette recherche contribue à approfondir la compréhension des conséquences liées au triclosan sur les marais filtrants, en plus de proposer la diversité végétale pour mitiger les impacts sur les communautés microbiennes. / Triclosan, a biocide now widely present in the environment, can have negative effects on exposed organisms. A blue infrastructure, treatment wetlands, is proposed as an appropriate solution to mitigate the risks associated with this contaminant. However, research is still incomplete on the impacts of triclosan on the ecological health and performance of this phytotechnology. The aim of my research project is therefore to establish the effects of triclosan in treatment wetland mesocosms. Thus, monocultures and polycultures of three plants native to Canada were studied, detailing the impacts of triclosan on the efficiency and ecosystem health of the experimental set-up. Although the plants selected had widely differing rates of removal of typical pollutants (ammonium, nitrite, nitrate, and orthophosphate), as well as extensively divergent biomass, unlike other studies, triclosan had no impact on these parameters. The pollutant did, however, adversely affect Eurtochium maculatum physiomorphologically, but Sporobulus michauxianus and Phragmites australis subsp. americanus showed signs of resilience. The oxidation-reduction potential as well as the algal and photosynthetic bacterial biomass of the effluent were significantly reduced in the presence of the contaminant. Triclosan also influenced the substrate and rhizosphere microbiota, notably by modifying the structure of bacterial communities and by significantly reducing the alpha diversity of the monoculture’s substrate. However, "polyculture" mesocosms exposed to triclosan appear to be more resilient, and in vivo BIOLOGTM EcoPlate characterization analysis of the community’s functionalities has even identified the possible degradation of molecule comparable to residual triclosan within the mesocosms. This research contributes to a deeper understanding of the consequences of triclosan on treatment wetlands, as well as proposing plant diversity to mitigate impacts on microbial communities.

Foram desenvolvidas metodologias de cromatografia a líquido de fase reversa baseadas em injeção sequencial (SIC) e em cromatografia a líquido de alta eficiência (HPLC) para determinação de triclosan em amostras de produtos de higiene pessoal e em estudos de adsorção em argilominerais naturais e modificados, visando determinar parâmetros de adsorção de triclosan frente a alguns de seus metabólitos. A determinação de triclosan em enxaguadores bucais foi realizada por SIC com eluição isocrática usando fase móvel constituída por acetonitrila: tampão fosfato de trietilamina 70 mM pH 3,5 na proporção 70:30 (v v-1), obtendo-se limites de detecção e de quantificação de 0,22 e 0,72 mg L-1, respectivamente. Taxas de recuperação entre 96 e 98% foram obtidas da aplicação a amostras reais, sendo que os resultados obtidos pelo método proposto não apresentaram evidências de diferenças estatisticamente significativas em comparação a uma metodologia de referência baseada em HPLC com coluna empacotada. A separação de triclosan (TCS), 2-clorofenol (2-CP), 2,4-diclorofenol (2,4-DCP), 2,4,6-triclorofenol (2,4,6-TCP), 2,3,4-triclorofenol (2,3,4-TCP) e metiltriclosan (MTCS) foi estudada por SIC, obtendo-se a separação de TCS, 2-CP, 2,4-DCP e 2,4,6-TCP com duas etapas de eluição isocrática, a primeira delas com fase móvel 60:40 (v v-1) metanol: tampão acetato de amônio 20 mM (pH 5,5) seguida de eluição com fase móvel 70:30 (v v-1) metanol : tampão acetato de amônio 20 mM (pH 5,5). Nesse caso, os isômeros 2,4,6-TCP e 2,3,4-TCP coeluem. Metiltriclosan, o menos polar desses compostos, pode ser separado de TCS com etapas subseqüentes de eluição. Os métodos foram aplicados para estudar a adsorção de triclosan e seus metabólitos 2,4-DCP, 2,4,6-TCP e metiltriclosan em montmorilonita homoiônica (K+) e modificada com sal de hexadeciltrimetilamônio (HDTMA), observando-se forte adsorção de triclosan e metiltriclosan em comparação a 2-CP, 2,4-DCP e 2,4,6-TCP. A incorporação de HDTMA no argilomineral causou significativo aumento da capacidade de adsorção desses metabólitos, determinada a partir do ajuste dos dados experimentais à equação linearizada de Langmuir, observando-se que a ordem de adsorção é 2,4,6-TCP > 2,4-DCP > 2-CP / Reversed-phase liquid chromatography methodologies based on sequential injection (SIC) and high performance liquid chromatography (HPLC) have been developed for determination of triclosan in samples of personal hygiene products and in studies of adsorption on natural and modified clay minerals aiming to determine kinetic and thermodynamic parameters of adsorption of triclosan in comparison with some of its metabolites. The determination of triclosan in oral rinses with SIC was performed by isocratic elution using a mobile phase of acetonitrile : 70 mM triethylamine phosphate buffer pH 3.5 at the ratio 70:30 (v v-1), obtaining limits of detection and quantification of 0.22 and 0.72 mg L-1, respectively. Recovery rates between 96 and 98 % were obtained from the application to commercial samples, and the results obtained by the proposed method showed no evidence of statistically significant differences compared to the reference methodology based on HPLC with packed column. The separation of triclosan (TCS), 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4 trichlorophenol (2,3,4-TCP) and methyltriclosan (MTCS) was studied by SIC, resulting in the separation of TCS, 2-CP, 2,4-DCP and 2,4,6-TCP with two isocratic elution steps, the first of them with a mobile phase 60:40 (v v-1) methanol: 20 mM ammonium acetate buffer (pH 5.5) followed by elution with 70:30 (v v-1) mobile phase of methanol : 20 mM ammonium acetate buffer (pH 5.5). In this case, the isomers 2,4,6-TCP and 2,3,4-TCP coeluted. Methyltriclosan, the less polar of these compounds, can be separated from TCS with subsequent elution steps. The methods were applied to study the adsorption of triclosan and its metabolites 2-CP, 2,4-DCP, 2,4,6-TCP and methyltriclosan on homoionic montmorillonite (K+) as well as in hexadecyltrimethylammonium salt (HDTMA) modified montmorillonite, noticing a stronger adsorption of triclosan and methyltriclosan compared with 2-CP, 2,4-DCP and 2,4,6-TCP. Incorporation of HDTMA in the clay mineral caused significant increase in adsorption capacity of these metabolites. This capacity was determined by fitting the experimental data to the linearized Langmuir equation. The adsorption order was 2,4,6-TCP > 2,4-DCP > 2-CP.

Foram desenvolvidas metodologias de cromatografia a líquido de fase reversa baseadas em injeção sequencial (SIC) e em cromatografia a líquido de alta eficiência (HPLC) para determinação de triclosan em amostras de produtos de higiene pessoal e em estudos de adsorção em argilominerais naturais e modificados, visando determinar parâmetros de adsorção de triclosan frente a alguns de seus metabólitos. A determinação de triclosan em enxaguadores bucais foi realizada por SIC com eluição isocrática usando fase móvel constituída por acetonitrila: tampão fosfato de trietilamina 70 mM pH 3,5 na proporção 70:30 (v v-1), obtendo-se limites de detecção e de quantificação de 0,22 e 0,72 mg L-1, respectivamente. Taxas de recuperação entre 96 e 98% foram obtidas da aplicação a amostras reais, sendo que os resultados obtidos pelo método proposto não apresentaram evidências de diferenças estatisticamente significativas em comparação a uma metodologia de referência baseada em HPLC com coluna empacotada. A separação de triclosan (TCS), 2-clorofenol (2-CP), 2,4-diclorofenol (2,4-DCP), 2,4,6-triclorofenol (2,4,6-TCP), 2,3,4-triclorofenol (2,3,4-TCP) e metiltriclosan (MTCS) foi estudada por SIC, obtendo-se a separação de TCS, 2-CP, 2,4-DCP e 2,4,6-TCP com duas etapas de eluição isocrática, a primeira delas com fase móvel 60:40 (v v-1) metanol: tampão acetato de amônio 20 mM (pH 5,5) seguida de eluição com fase móvel 70:30 (v v-1) metanol : tampão acetato de amônio 20 mM (pH 5,5). Nesse caso, os isômeros 2,4,6-TCP e 2,3,4-TCP coeluem. Metiltriclosan, o menos polar desses compostos, pode ser separado de TCS com etapas subseqüentes de eluição. Os métodos foram aplicados para estudar a adsorção de triclosan e seus metabólitos 2,4-DCP, 2,4,6-TCP e metiltriclosan em montmorilonita homoiônica (K+) e modificada com sal de hexadeciltrimetilamônio (HDTMA), observando-se forte adsorção de triclosan e metiltriclosan em comparação a 2-CP, 2,4-DCP e 2,4,6-TCP. A incorporação de HDTMA no argilomineral causou significativo aumento da capacidade de adsorção desses metabólitos, determinada a partir do ajuste dos dados experimentais à equação linearizada de Langmuir, observando-se que a ordem de adsorção é 2,4,6-TCP > 2,4-DCP > 2-CP / Reversed-phase liquid chromatography methodologies based on sequential injection (SIC) and high performance liquid chromatography (HPLC) have been developed for determination of triclosan in samples of personal hygiene products and in studies of adsorption on natural and modified clay minerals aiming to determine kinetic and thermodynamic parameters of adsorption of triclosan in comparison with some of its metabolites. The determination of triclosan in oral rinses with SIC was performed by isocratic elution using a mobile phase of acetonitrile : 70 mM triethylamine phosphate buffer pH 3.5 at the ratio 70:30 (v v-1), obtaining limits of detection and quantification of 0.22 and 0.72 mg L-1, respectively. Recovery rates between 96 and 98 % were obtained from the application to commercial samples, and the results obtained by the proposed method showed no evidence of statistically significant differences compared to the reference methodology based on HPLC with packed column. The separation of triclosan (TCS), 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4 trichlorophenol (2,3,4-TCP) and methyltriclosan (MTCS) was studied by SIC, resulting in the separation of TCS, 2-CP, 2,4-DCP and 2,4,6-TCP with two isocratic elution steps, the first of them with a mobile phase 60:40 (v v-1) methanol: 20 mM ammonium acetate buffer (pH 5.5) followed by elution with 70:30 (v v-1) mobile phase of methanol : 20 mM ammonium acetate buffer (pH 5.5). In this case, the isomers 2,4,6-TCP and 2,3,4-TCP coeluted. Methyltriclosan, the less polar of these compounds, can be separated from TCS with subsequent elution steps. The methods were applied to study the adsorption of triclosan and its metabolites 2-CP, 2,4-DCP, 2,4,6-TCP and methyltriclosan on homoionic montmorillonite (K+) as well as in hexadecyltrimethylammonium salt (HDTMA) modified montmorillonite, noticing a stronger adsorption of triclosan and methyltriclosan compared with 2-CP, 2,4-DCP and 2,4,6-TCP. Incorporation of HDTMA in the clay mineral caused significant increase in adsorption capacity of these metabolites. This capacity was determined by fitting the experimental data to the linearized Langmuir equation. The adsorption order was 2,4,6-TCP > 2,4-DCP > 2-CP.

<div>Biosolids-based fertilizers are sold to the public to provide beneficial nutrients and organic matter for plant production. They are commonly applied to community gardens, municipal lands, reclamation projects, and golf courses. These fertilizers, however, may also contain a variety of trace organic contaminants, which can be persistent in the environment. Our work sought to quantify the persistence of biosolids contaminants in community garden soils. The commercial biosolids-based fertilizer, OCEANGRO®, was amended to two community garden soils to determine the first-order half-lives of four model contaminants: carbamazepine, miconazole, triclocarban, and triclosan. The criteria for their selection included biosolids occurrence, ecotoxicity, antimicrobial function, and knowledge gaps. Aerobic biosolids-amended soil microcosms were incubated at 22 ± 1 °C and approximately 80% field capacity. Sacrificial sampling occurred seven times over 180 days through multi-step solvent extractions. Detection and quantification were done on a high-performance liquid chromatograph tandem triple-quadrupole mass spectrometer. Results indicated that biosolids contaminants persist in soils with some having modeled half-lives in the hundreds of days. Additional analyses of solvent-spiked contaminant degradation and porewater desorption were performed to provide greater insight into possible limitations on resident biosolids contaminant degradation and to form a better comparative basis to previous literature. Solvent-spiked contaminants degraded more quickly than those resident within biosolids, which indicate that data using the former may underestimate persistence in real-world environments. The porewater analysis allowed for the desorption coefficient to be calculated for all four model resident contaminants. Disparities in the trends of these desorption coefficients and solvent-spiked degradation rates showed that desorption from the biosolids matrix may have been a limiting factor to resident degradation for only some of our four model contaminants. Nonetheless, the demonstrated persistence of these contaminants necessitates long-term thinking in relation to biosolids application. More work is needed on the potential hazards associated with biosolids use in public lands regarding ecotoxicity and antimicrobial resistance.</div>

Decabromodiphenylether (deca-BDE) and triclosan (2,4,4'-trichloro-2'-hydroxydiphenylether) are used in consumer products as flame retardant and bactericide, respectively. Dermal contact is a major human exposure pathway. Deca-BDE and triclosan are known to be photolytically degraded to compounds like lower-BDEs and dioxins. My hypothesis is that photolysis of deca-BDE and triclosan generates free radicals and degradation products which cause toxic effects including cytotoxicity, growth inhibition, oxidative stress and genotoxicity in skin. To test this hypothesis radical formation and photolytic products of deca-BDE and toxic effects of deca-BDE and triclosan alone/with UV-exposure were determined using immortal human keratinocytes (HaCaT) and primary human skin fibroblasts (HSF). My electron paramagnetic resonance and GC-MS studies indicate that deca-BDE is photoreactive and UV irradiation of deca-BDE in organic solvents generates free radicals and lower-BDEs. The free radical formation is wavelength-dependent and positively related to the irradiation time and deca-BDE concentration. In structure-activity relationship studies with deca-BDE, octa-BDE, PBB 209, PCB 209 and diphenyl ether, the presence of halogen atoms (Br > Cl), and/or an ether bond enhance free radical formation. Debromination and hydrogen abstraction from the solvents are the mechanism of radical formation with deca-BDE, which raises concerns about possible toxic effects in UV-exposed skin. In cell culture experiments high levels of triclosan plus UV irradiation and repetitive deca-BDE and UV exposures caused synergistic cytotoxicity in HaCaT. However, neither triclosan nor deca-BDE can be regarded as a phototoxicant following the OECD test and evaluation guidelines. In HSF, no synergistic cytotoxicity was observed, although HSF were more sensitive to deca-BDE and triclosan alone than HaCaT. Contrary to expectations, the photodegradation products of triclosan were less toxic than triclosan itself to HaCaT. However, UV irradiation of triclosan-exposed cells produced a dose dependent increase in intracellular oxidative stress (dichlorofluorescein formation). Comet experiments did not show consistent results of genotoxicity in HaCaT. Overall, deca-BDE and triclosan had no or weak phototoxic potential in cells with the experimental conditions employed. To my knowledge, my research is the first prove of free radical formation during UV irradiation of deca-BDE and the first investigation of phototoxicity of deca-BDE and triclosan in human skin cells.

Triclosan and triclocarban are antimicrobials found in numerous consumer products, while caffeine is the most commonly consumed stimulant by humans. This study was undertaken to determine the effects of triclosan, triclocarban, and caffeine on the development and physiology of amphibian larvae. LC50 values of triclosan and triclocarban were determined after 96 hours for three North American larval species: Acris crepitans blanchardii, Bufo woodhousii woodhousii, Rana sphenocephala, and for a common amphibian developmental model: Xenopus laevis. Amphibian larvae were most sensitive to triclosan and triclocarban exposure during early development based upon 96-hour LC50 values. Heart rates for X. laevis and North American larvae exposed to triclosan were variable throughout development. However, significantly lower heart rates were observed in all larvae exposed to triclocarban. Metabolic rates of X. laevis and R. sphenocephala larvae exposed to triclosan were significantly affected in larvae exposed to ½ LC50 and the LC50 concentration. Metabolic rates of X. laevis larvae exposed to triclocarban were significantly affected by exposure to ½ LC50 concentrations in three of four stages investigated. No significant differences were observed in North American larvae exposed to triclocarban. Tissue uptake, lipid uptake, tissue bioconcentration factor (BCF) and lipid BCF of triclosan and triclocarban were investigated in three developmental stages of X. laevis, and in one developmental stage of B. woodhousii woodhousii, and R. sphenocephala. For most tissue and lipid uptake values, a significant increase was observed as exposure concentration increased. Tissue and lipid BCF values were dependent upon both stage and species. Chronic and acute effects of caffeine were determined in X. laevis larvae. Acute 96-hour LC50 values in four developmental stages were > 75,000 ug L-1 caffeine and heart rates were significantly different at the two earliest developmental stages. Larvae chronically exposed to caffeine reached metamorphosis at the same time as controls. Changes in chronic heart rate were dependent upon stage of development and exposure concentration. This research indicates that the toxicity of amphibian larvae exposed to triclosan, triclocarban, and caffeine appears to be dependent upon species and developmental stage, with early developmental stages being most sensitive to contaminant exposure.

No description available.

Metal oxide-facilitated transformation is likely an important degradation pathway of antibacterial agents at soil-water interfaces. Phenolic disinfectants (triclosan and chlorophene), fluoroquinolones (FQs), and aromatic N-oxides are of particular concern due to their widespread usage, potential toxicity and frequent detection in the environment. Results of the present study show that the above antibacterial agents are highly susceptible to metal oxide-facilitated oxidation. The interfacial reactions exhibit complex reaction kinetics, which are affected by solution pH, the presence of co-solutes, surface properties of metal oxides, and structural characteristics of antibacterial agents. Adsorption of the antibacterial agents to Mn and Fe oxide surfaces generally proceeds faster than oxidation reactions of these compounds by Mn and Fe oxides, especially in the case of Fe oxides. Reaction intermediates and end products are identified by GC/MS, LC/MS and/or FTIR. Structurally-related model compounds are examined to facilitate reaction site and mechanism elucidation. On the basis of experimental results and literature, reaction schemes are proposed. In general, the antibacterial agent is adsorbed to the oxide surface, forming a precursor complex. Electrons are transferred within the precursor complex from the antibacterial agent to the oxide, followed by releasing of the radical intermediates which undergo further reactions to generate oxidation products. The precursor complex formation and electron transfer are likely rate-limiting. For triclosan, phenoxy radicals are critical intermediates to form oxidation products through three pathways (i.e., radical coupling, further oxidation of the radical, and breakdown of an ether bond within the radical). The first two pathways are also operative in the oxidation of chlorophene. For FQs, oxidation generates radical intermediates that are most likely centered on the inner N in the piperazine ring. The radical intermediates then undergo three major pathways (i.e., radical coupling, N-dealkylation, and hydroxylation) to yield a variety of products. For aromatic N-oxides, a N-oxide radical intermediate is generated upon oxidation by MnO2, followed by the loss of oxygen from the N-oxide moiety and the formation of a hydroxyl group at the C-atom adjacent to the N-oxide moiety. Overall, a fundamental understanding of the reaction mechanisms between three classes of antibacterial agents and metal oxides has been obtained.