خيارات البحث
النتائج 431 - 440 من 1,324
Mechanisms of enhanced mobilisation of trace metals by anionic surfactants in soil النص الكامل
2011
Hernández-Soriano, Maria del Carmen | Degryse, Fien | Smolders, Erik
Mechanisms of enhanced mobilisation of trace metals by anionic surfactants in soil النص الكامل
2011
Hernández-Soriano, Maria del Carmen | Degryse, Fien | Smolders, Erik
Long-term applications of small concentrations of surfactants in soil via wastewater irrigation or pesticide application may enhance trace metal solubility. Mechanisms by which anionic surfactants (Aerosol 22, SDS and Biopower) affect trace metal solubility were assessed using batch, incubation and column experiments. In batch experiments on seven soils, the concentrations of Cu, Cd, Ni and Zn in the dissolved fraction of soils increased up to 100-fold at the high application rates, but increased less than 1.5-fold below the critical micelle concentration. Dissolved metal concentrations were less than 20% affected by surfactants in long-term incubations (70 days) up to the largest dose of 200 mg C kg⁻¹ soil. Leaching soil columns with A22 (100–1000 mg C L⁻¹) under unsaturated conditions increased trace metal concentrations in the leachates 2–4 fold over the control. Correlation analysis and speciation modelling showed that the increased solubility of metals upon surfactant application was more related to the solubilisation of soil organic matter from soil than to complexation of the metals with the surfactant. Organic matter from soil was solubilised in response to a decrease of solution Ca²⁺ as a result of Ca–surfactant precipitation. At environmentally relevant concentrations, surfactant application is unlikely to have a significant effect on trace metal mobility.
اظهر المزيد [+] اقل [-]Mechanisms of enhanced mobilisation of trace metals by anionic surfactants in soil النص الكامل
2011
Hernández-Soriano, M.D.C. | Degryse, F. | Smolders, E.
Abstract not available | Maria del Carmen Hernández-Soriano, Fien Degryse and Erik Smolders
اظهر المزيد [+] اقل [-]Groundwater quality assessment of one former industrial site in Belgium using a TRIAD-like approach النص الكامل
2011
Crévecoeur, Sophie | Debacker, Virginie | Joaquim-Justo, Célia | Gobert, Sylvie | Scippo, Marie-Louise | Dejonghe, Winnie | Martin, Patrick | Thomé, Jean-Pierre
Groundwater quality assessment of one former industrial site in Belgium using a TRIAD-like approach النص الكامل
2011
Crévecoeur, Sophie | Debacker, Virginie | Joaquim-Justo, Célia | Gobert, Sylvie | Scippo, Marie-Louise | Dejonghe, Winnie | Martin, Patrick | Thomé, Jean-Pierre
Contaminated industrial sites are important sources of pollution and may result in ecotoxicological effects on terrestrial, aquatic and groundwater ecosystems. An effect-based approach to evaluate and assess pollution-induced degradation due to contaminated groundwater was carried out in this study. The new concept, referred to as “Groundwater Quality TRIAD-like” (GwQT) approach, is adapted from classical TRIAD approaches. GwQT is based on measurements of chemical concentrations, laboratory toxicity tests and physico-chemical analyses. These components are combined in the GwQT using qualitative and quantitative (using zero to one subindices) integration approaches. The TRIAD approach is applied for the first time on groundwater from one former industrial site located in Belgium. This approach will allow the classification of sites into categories according to the degree of contaminant-induced degradation. This new concept is a starting point for groundwater characterization and is open for improvement and adjustment.
اظهر المزيد [+] اقل [-]Groundwater quality assessment of one former industrial site in Belgium using a TRIAD-like approach. | Evaluation de la qualité des eaux souterraines d'une friche industrielle belge suivant la méthodologie TRIAD. النص الكامل
2011
Crévecoeur, Sophie | Debacker, Virginie | Joaquim-Justo, Célia | Gobert, Sylvie | Scippo, Marie-Louise | Dejonghe, Winnie | Martin, Patrick | Thomé, Jean-Pierre
Contaminated industrial sites are important sources of pollution and may result in ecotoxicological effects on terrestrial, aquatic and groundwater ecosystems. An effect-based approach to evaluate and assess pollution-induced degradation due to contaminated groundwater was carried out in this study.The new concept, referred to as “Groundwater Quality TRIAD-like” (GwQT) approach, is adapted from classical TRIAD approaches. GwQT is based on measurements of chemical concentrations, laboratory toxicity tests and physico-chemical analyses. These components are combined in the GwQT using qualitative and quantitative (using zero to one subindices)integration approaches. The TRIAD approach is applied for the first time on groundwater from one former industrial site located in Belgium. This approach will allow the classification of sites into categories according to the degree of contaminant-induced degradation. This new concept is a starting point for groundwater characterization and is open for improvement and adjustment. | Science of Sustainable Development (FRAC-WECO project, 2007-2010).
اظهر المزيد [+] اقل [-]Groundwater quality assessment of one former industrial site in Belgium using a TRIAD-like approach. | Evaluation de la qualité des eaux souterraines d'une friche industrielle belge suivant la méthodologie TRIAD. النص الكامل
2011
Crévecoeur, Sophie | Debacker, Virginie | Joaquim-Justo, Célia | Gobert, Sylvie | Scippo, Marie-Louise | Dejonghe, Winnie | Martin, Patrick | Thomé, Jean-Pierre
peer reviewed | Contaminated industrial sites are important sources of pollution and may result in ecotoxicological effects on terrestrial, aquatic and groundwater ecosystems. An effect-based approach to evaluate and assess pollution-induced degradation due to contaminated groundwater was carried out in this study. The new concept, referred to as “Groundwater Quality TRIAD-like” (GwQT) approach, is adapted from classical TRIAD approaches. GwQT is based on measurements of chemical concentrations, laboratory toxicity tests and physico-chemical analyses. These components are combined in the GwQT using qualitative and quantitative (using zero to one subindices)integration approaches. The TRIAD approach is applied for the first time on groundwater from one former industrial site located in Belgium. This approach will allow the classification of sites into categories according to the degree of contaminant-induced degradation. This new concept is a starting point for groundwater characterization and is open for improvement and adjustment. | Science of Sustainable Development (FRAC-WECO project, 2007-2010).
اظهر المزيد [+] اقل [-]TiO₂-based nanoparticles released in water from commercialized sunscreens in a life-cycle perspective: Structures and quantities النص الكامل
2011
Botta, Céline | Labille, Jérôme | Auffan, Mélanie | Borschneck, Daniel | Miche, Hélène | Cabié, Martiane | Masion, Armand | Rose, Jerome | Bottero, Jean-Yves
TiO₂-based nanoparticles released in water from commercialized sunscreens in a life-cycle perspective: Structures and quantities النص الكامل
2011
Botta, Céline | Labille, Jérôme | Auffan, Mélanie | Borschneck, Daniel | Miche, Hélène | Cabié, Martiane | Masion, Armand | Rose, Jerome | Bottero, Jean-Yves
This work investigates the physical–chemical evolution during artificial aging in water of four commercialized sunscreens containing TiO₂-based nanocomposites. Sunscreens were analyzed in terms of mineralogy and TiO₂ concentration. The residues formed after aging were characterized in size, shape, chemistry and surface properties. The results showed that a significant fraction of nano-TiO₂ residues was released from all sunscreens, despite their heterogeneous behaviors. A stable dispersion of submicronic aggregates of nanoparticles was generated, representing up to 38w/w% of the amount of sunscreen, and containing up to 30% of the total nano-TiO₂ initially present in the creams. The stability of the dispersion was tested as a function of salt concentration, revealing that in seawater conditions, a major part of these nano-TiO₂ residues will aggregate and sediment. These results were put in perspective with consumption and life cycle of sunscreens to estimate the amount of nano-TiO₂ potentially released into AQUATIC environment.
اظهر المزيد [+] اقل [-]TiO2-based nanoparticles released in water from commercialized sunscreens in a life-cycle perspective: Structures and quantities النص الكامل
2011
Botta, Céline | Labille, Jérôme | Auffan, Melanie | Borschneck, Daniel | Miche, Helene | Cabié, Martiane | Masion, Armand | Rose, Jérôme | Bottero, Jean-Yves | Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE) ; Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) | Spectropôle - Aix Marseille Université (AMU SPEC) ; Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
International audience | This work investigates the physical-chemical evolution during artificial aging in water of four commercialized sunscreens containing TiO2-based nanocomposites. Sunscreens were analyzed in terms of mineralogy and TiO2 concentration. The residues formed after aging were characterized in size, shape, chemistry and surface properties. The results showed that a significant fraction of nano-TiO2 residues was released from all sunscreens, despite their heterogeneous behaviors. A stable dispersion of submicronic aggregates of nanoparticles was generated, representing up to 38 w/w% of the amount of sunscreen, and containing up to 30% of the total nano-TiO2 initially present in the creams. The stability of the dispersion was tested as a function of salt concentration, revealing that in seawater conditions, a major part of these nano-TiO2 residues will aggregate and sediment. These results were put in perspective with consumption and life cycle of sunscreens to estimate the amount of nano-TiO2 potentially released into AQUATIC environment. (C) 2011 Elsevier Ltd. All rights reserved.
اظهر المزيد [+] اقل [-]Molecular effects and bioaccumulation of levonorgestrel in the non-target organism Dreissena polymorpha النص الكامل
2011
Contardo-Jara, Valeska | Lorenz, Claudia | Pflugmacher, Stephan | Nützmann, Gunnar | Kloas, Werner | Wiegand, Claudia
Molecular effects and bioaccumulation of levonorgestrel in the non-target organism Dreissena polymorpha النص الكامل
2011
Contardo-Jara, Valeska | Lorenz, Claudia | Pflugmacher, Stephan | Nützmann, Gunnar | Kloas, Werner | Wiegand, Claudia
Bioaccumulation and effects of the contraceptive hormone levonorgestrel were examined in the non-target organism Dreissena polymorpha. Molecular biomarkers of biotransformation, elimination, antioxidant defence and protein damage were analyzed after exposure to increasing concentrations of levonorgestrel in a flow-through system. The lowest concentration (0.312 μg L⁻¹) was 100-fold bioconcentrated within four days. A decrease of the bioconcentration factor was observed within one week for the highest test concentrations (3.12 and 6.24 μg L⁻¹) suggesting enhanced excretory processes. The immediate mRNA up-regulation of pi class glutathione S-transferase proved that phase II biotransformation processes were induced. Disturbance of fundamental cell functions was assumed since the aryl hydrocarbon receptor has been permanently down-regulated. mRNA up-regulation of P-glycoprotein, superoxide dismutase and metallothioneine suggested enhanced elimination processes and ongoing oxidative stress. mRNA up-regulation of heat shock protein 70 in mussels exposed to the two highest concentrations clearly indicated impacts on protein damage.
اظهر المزيد [+] اقل [-]Molecular effects and bioaccumulation of levonorgestrel in the non-target organism Dreissena polymorpha النص الكامل
2011
Contardo-Jara, Valeska | Lorenz, Claudia | Pflugmacher, Stephan | Nutzmann, Gunnar | Kloas, Werner | Wiegand, Claudia | Department of Ecophysiology and Aquaculture [Berlin] ; Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) | Ecohydrology, Leibniz Berlin ; Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) | Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO) ; Université de Rennes (UR)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des sciences de l'environnement de Rennes (OSERen) ; Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | University of Southern Denmark (SDU)
International audience | Bioaccumulation and effects of the contraceptive hormone levonorgestrel were examined in the nontarget organism Dreissena polymorpha. Molecular biomarkers of biotransformation, elimination, antioxidant defence and protein damage were analyzed after exposure to increasing concentrations of levonorgestrel in a flow-through system. The lowest concentration (0.312 mg L-1) was 100-fold bioconcentrated within four days. A decrease of the bioconcentration factor was observed within one week for the highest test concentrations (3.12 and 6.24 mg L-1) suggesting enhanced excretory processes. The immediate mRNA up-regulation of pi class glutathione S-transferase proved that phase II biotransformation processes were induced. Disturbance of fundamental cell functions was assumed since the aryl hydrocarbon receptor has been permanently down-regulated. mRNA up-regulation of P-glycoprotein, superoxide dismutase and metallothioneine suggested enhanced elimination processes and ongoing oxidative stress. mRNA up-regulation of heat shock protein 70 in mussels exposed to the two highest concentrations clearly indicated impacts on protein damage.
اظهر المزيد [+] اقل [-]Open Air Laboratories (OPAL): A community-driven research programme النص الكامل
2011
Davies, L. | Bell, J.N.B. | Bone, J. | Creagh-Henry, M. (May) | Hill, L. | Howard, C. | Hobbs, S.J. | Jones, D.T. | Power, S.A. | Rose, N. | Ryder, C. | Seed, L. | Stevens, G. | Toumi, R. | Voulvoulis, N. | White, P.C.L.
Open Air Laboratories (OPAL): A community-driven research programme النص الكامل
2011
Davies, L. | Bell, J.N.B. | Bone, J. | Creagh-Henry, M. (May) | Hill, L. | Howard, C. | Hobbs, S.J. | Jones, D.T. | Power, S.A. | Rose, N. | Ryder, C. | Seed, L. | Stevens, G. | Toumi, R. | Voulvoulis, N. | White, P.C.L.
OPAL is an English national programme that takes scientists into the community to investigate environmental issues. Biological monitoring plays a pivotal role covering topics of: i) soil and earthworms; ii) air, lichens and tar spot on sycamore; iii) water and aquatic invertebrates; iv) biodiversity and hedgerows; v) climate, clouds and thermal comfort. Each survey has been developed by an inter-disciplinary team and tested by voluntary, statutory and community sectors. Data are submitted via the web and instantly mapped. Preliminary results are presented, together with a discussion on data quality and uncertainty. Communities also investigate local pollution issues, ranging from nitrogen deposition on heathlands to traffic emissions on roadside vegetation. Over 200,000 people have participated so far, including over 1000 schools and 1000 voluntary groups. Benefits include a substantial, growing database on biodiversity and habitat condition, much from previously unsampled sites particularly in urban areas, and a more engaged public.
اظهر المزيد [+] اقل [-]Open Air Laboratories (OPAL): a community-driven research programme النص الكامل
2011
Davies, Linda | Bell, J. N. B. | Bone, J. | Head, M. | Hill, L. | Howard, C. | Hobbs, S. J. | Jones, D. T. | Power, S. A. | Rose, N. | Ryder, Claire | Seed, L. | Stevens, G. | Toumi, R. | Voulvoulis, N. | White, P. C. L.
OPAL is an English national programme that takes scientists into the community to investigate environmental issues. Biological monitoring plays a pivotal role covering topics of: i) soil and earthworms; ii) air, lichens and tar spot on sycamore; iii) water and aquatic invertebrates; iv) biodiversity and hedgerows; v) climate, clouds and thermal comfort. Each survey has been developed by an interdisciplinary team and tested by voluntary, statutory and community sectors. Data are submitted via the web and instantly mapped. Preliminary results are presented, together with a discussion on data quality and uncertainty. Communities also investigate local pollution issues, ranging from nitrogen deposition on heathlands to traffic emissions on roadside vegetation. Over 200,000 people have participated so far, including over 1000 schools and 1000 voluntary groups. Benefits include a substantial, growing database on biodiversity and habitat condition, much from previously unsampled sites particularly in urban areas, and a more engaged public.
اظهر المزيد [+] اقل [-]Impact of atmospheric deposition of anthropogenic and natural trace metals on Northwestern Mediterranean surface waters: A box model assessment النص الكامل
2011
Heimbürger, Lars-Eric | Migon, Christophe | Cossa, Daniel
Impact of atmospheric deposition of anthropogenic and natural trace metals on Northwestern Mediterranean surface waters: A box model assessment النص الكامل
2011
Heimbürger, Lars-Eric | Migon, Christophe | Cossa, Daniel
Under stratified oligotrophic conditions (May–November), the surface mixed layer of the Northwestern Mediterranean constitutes a homogeneous water volume of 10–30m depth. In other respects, the mean residence time of Ligurian surface waters (0–200m) is 102 days. It is therefore possible to quantify the extent to which atmospheric deposition of trace metals affects surface waters. On the basis of literature data on anthropogenic and natural trace metals, we demonstrate that the ratios between total seawater labile atmospheric deposition during 102 days (Δc) and dissolved TM concentrations in Ligurian surface waters (c) illustrate the impact of atmospheric deposition on surface seawater (Δc/c). High ratios indicate surface TM enrichments, while low ratios indicate surface TM depletion, due to the quasi-complete sorption and removal of TMs by plankton during spring bloom. The simple box model proposed here may be used for other marine regions where hydrodynamical and physico-chemical constraints are well defined.
اظهر المزيد [+] اقل [-]Impact of atmospheric deposition of anthropogenic and natural trace metals on Northwestern Mediterranean surface waters: A box model assessment النص الكامل
2011
Heimbuerger, Lars-eric | Migon, Christophe | Cossa, Daniel
Under stratified oligotrophic conditions (May November), the surface mixed layer of the Northwestern Mediterranean constitutes a homogeneous water volume of 10-30 m depth. In other respects, the mean residence time of Ligurian surface waters (0-200 m) is 102 days. It is therefore possible to quantify the extent to which atmospheric deposition of trace metals affects surface waters. On the basis of literature data on anthropogenic and natural trace metals, we demonstrate that the ratios between total seawater labile atmospheric deposition during 102 days (Delta c) and dissolved TM concentrations in Ligurian surface waters (c) illustrate the impact of atmospheric deposition on surface seawater (Delta c/c). High ratios indicate surface TM enrichments, while low ratios indicate surface TM depletion, due to the quasi-complete sorption and removal of TMs by plankton during spring bloom. The simple box model proposed here may be used for other marine regions where hydrodynamical and physico-chemical constraints are well defined. (C) 2011 Elsevier Ltd. All rights reserved.
اظهر المزيد [+] اقل [-]Spatiotemporal dynamics of spring and stream water chemistry in a high-mountain area النص الكامل
2011
Żelazny, Mirosław | Astel, Aleksander | Wolanin, Anna | Małek, Stanisław
Spatiotemporal dynamics of spring and stream water chemistry in a high-mountain area النص الكامل
2011
Żelazny, Mirosław | Astel, Aleksander | Wolanin, Anna | Małek, Stanisław
The present study deals with the application of the self-organizing map (SOM) technique in the exploration of spatiotemporal dynamics of spring and stream water samples collected in the Chochołowski Stream Basin located in the Tatra Mountains (Poland). The SOM-based classification helped to uncover relationships between physical and chemical parameters of water samples and factors determining the quality of water in the studied high-mountain area. In the upper part of the Chochołowski Stream Basin, located on the top of the crystalline core of the Tatras, concentrations of the majority of ionic substances were the lowest due to limited leaching. Significantly higher concentration of ionic substances was detected in spring and stream samples draining sedimentary rocks. The influence of karst-type springs on the quality of stream water was also demonstrated.
اظهر المزيد [+] اقل [-]Spatiotemporal dynamics of spring and stream water chemistry in a high-mountain area النص الكامل
Żelazny Mirosław | Aleksander Astel | Anna Wolanin | Stanisław Małek
The present study deals with the application of the self-organizing map (SOM) technique in the exploration of spatiotemporal dynamics of spring and stream water samples collected in the Chochołowski Stream Basin located in the Tatra Mountains (Poland). The SOM-based classification helped to uncover relationships between physical and chemical parameters of water samples and factors determining the quality of water in the studied high-mountain area. In the upper part of the Chochołowski Stream Basin, located on the top of the crystalline core of the Tatras, concentrations of the majority of ionic substances were the lowest due to limited leaching. Significantly higher concentration of ionic substances was detected in spring and stream samples draining sedimentary rocks. The influence of karst-type springs on the quality of stream water was also demonstrated. | Tatra Mountains Basin Water chemical profile Unsupervised classification Self-organizing maps Rock Spruce stands | 40 | 1048-1057 | 159
اظهر المزيد [+] اقل [-]Effects of biochar and the earthworm Eisenia fetida on the bioavailability of polycyclic aromatic hydrocarbons and potentially toxic elements النص الكامل
2011
Gomez-Eyles, Jose L. | Sizmur, Tom | Collins, Chris D. | Hodson, Mark E.
Effects of biochar and the earthworm Eisenia fetida on the bioavailability of polycyclic aromatic hydrocarbons and potentially toxic elements النص الكامل
2011
Gomez-Eyles, Jose L. | Sizmur, Tom | Collins, Chris D. | Hodson, Mark E.
Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) were monitored over 56 days in calcareous contaminated-soil amended with either or both biochar and Eisenia fetida. Biochar reduced total (449 to 306mgkg⁻¹) and bioavailable (cyclodextrin extractable) (276 to 182mgkg⁻¹) PAHs, PAH concentrations in E. fetida (up to 45%) but also earthworm weight. Earthworms increased PAH bioavailability by >40%. Combined treatment results were similar to the biochar-only treatment. Earthworms increased water soluble Co (3.4 to 29.2mgkg⁻¹), Cu (60.0 to 120.1mgkg⁻¹) and Ni (31.7 to 83.0mgkg⁻¹) but not As, Cd, Pb or Zn; biochar reduced water soluble Cu (60 to 37mgkg⁻¹). Combined treatment results were similar to the biochar-only treatment but gave a greater reduction in As and Cd mobility. Biochar has contaminated land remediation potential, but its long-term impact on contaminants and soil biota needs to be assessed.
اظهر المزيد [+] اقل [-]Effects of biochar and the earthworm Eisenia fetida on the bioavailability of polycyclic aromatic hydrocarbons and potentially toxic elements النص الكامل
2011
Gomez-Eyles, Jose L. | Sizmur, Tom | Collins, Christopher David | Hodson, Mark Edward
Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) were monitored over 56 days in calcareous contaminated-soil amended with either or both biochar and Eisenia fetida. Biochar reduced total (449 to 306mgkg(-1)) and bioavailable (cyclodextrin extractable) (276 to 182mgkg(-1)) PAHs, PAH concentrations in E. fetida (up to 45%) but also earthworm weight. Earthworms increased PAH bioavailability by >40%. Combined treatment results were similar to the biochar-only treatment. Earthworms increased water soluble Co (3.4 to 29.2mgkg(-1)), Cu (60.0 to 120.1mgkg(-1)) and Ni (31.7 to 83.0mgkg(-1)) but not As, Cd, Pb or Zn; biochar reduced water soluble Cu (60 to 37mgkg(-1)). Combined treatment results were similar to the biochar-only treatment but gave a greater reduction in As and Cd mobility. Biochar has contaminated land remediation potential, but its long-term impact on contaminants and soil biota needs to be assessed.
اظهر المزيد [+] اقل [-]Environmental impact of sunscreen nanomaterials: Ecotoxicity and genotoxicity of altered TiO₂ nanocomposites on Vicia faba النص الكامل
2011
Foltête, Anne-Sophie | Masfaraud, Jean-François | Bigorgne, Emilie | Nahmani, Johanne | Chaurand, Perrine | Botta, Céline | Labille, Jérôme | Rose, Jerome | Férard, Jean-François | Cotelle, Sylvie
Environmental impact of sunscreen nanomaterials: Ecotoxicity and genotoxicity of altered TiO₂ nanocomposites on Vicia faba النص الكامل
2011
Foltête, Anne-Sophie | Masfaraud, Jean-François | Bigorgne, Emilie | Nahmani, Johanne | Chaurand, Perrine | Botta, Céline | Labille, Jérôme | Rose, Jerome | Férard, Jean-François | Cotelle, Sylvie
Mineral sunscreen nanocomposites, based on a nano-TiO₂ core, coated with aluminium hydroxide and dimethicone films, were submitted to an artificial ageing process. The resulting Altered TiO₂ Nanocomposites (ATN) were then tested in the liquid phase on the plant model Vicia faba, which was exposed 48 h to three nominal concentrations: 5, 25 and 50 mg ATN/L. Plant growth, photosystem II maximum quantum yield, genotoxicity (micronucleus test) and phytochelatins levels showed no change compared to controls. Oxidative stress biomarkers remained unchanged in shoots while in roots, glutathione reductase activity decreased at 50 mg ATN/L and ascorbate peroxidase activity decreased for 5 and 25 mg ATN/L. Nevertheless, despite the weak response of biological endpoints, ICP-MS measurements revealed high Ti and Al concentrations in roots, and X-ray fluorescence micro-spectroscopy revealed titanium internalization in superficial root tissues. Eventual long-term effects on plants may occur.
اظهر المزيد [+] اقل [-]Environmental impact of sunscreen nanomaterials: Ecotoxicity and genotoxicity of altered TiO2 nanocomposites on Vicia faba النص الكامل
2011
Foltete, Anne-Sophie | Masfaraud, Jean-Francois | Bigorgne, Emilie | Nahmani, J. | Chaurand, Perrine | Botta, Céline | Labille, Jérôme | Rose, Jérôme | Ferard, Jean-Francois | Cotelle, Sylvie | Laboratoire des Interactions Ecotoxicologie, Biodiversité, Ecosystèmes (LIEBE) ; Université Paul Verlaine - Metz (UPVM)-Centre National de la Recherche Scientifique (CNRS) | Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE) ; Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
International audience | Mineral sunscreen nanocomposites, based on a nano-TiO2 core, coated with aluminium hydroxide and dimethicone films, were submitted to an artificial ageing process. The resulting Altered TiO2 Nanocomposites (ATN) were then tested in the liquid phase on the plant model Vicia faba, which was exposed 48 h to three nominal concentrations: 5, 25 and 50 mg ATN/L Plant growth, photosystem II maximum quantum yield, genotoxicity (micronucleus test) and phytochelatins levels showed no change compared to controls. Oxidative stress biomarkers remained unchanged in shoots while in roots, glutathione reductase activity decreased at 50 mg ATN/L and ascorbate peroxidase activity decreased for 5 and 25 mg ATN/L. Nevertheless, despite the weak response of biological endpoints, ICP-MS measurements revealed high Ti and Al concentrations in roots, and X-ray fluorescence micro-spectroscopy revealed titanium internalization in superficial root tissues. Eventual long-term effects on plants may occur.
اظهر المزيد [+] اقل [-]The definition of species richness used by species sensitivity distributions approximates observed effects of salinity on stream macroinvertebrates النص الكامل
2011
Kefford, Ben J. | Marchant, Richard | Schäfer, Ralf B. | Metzeling, Leon | Dunlop, Jason E. | Choy, S. C. (Satish C.) | Goonan, Peter
The definition of species richness used by species sensitivity distributions approximates observed effects of salinity on stream macroinvertebrates النص الكامل
2011
Kefford, Ben J. | Marchant, Richard | Schäfer, Ralf B. | Metzeling, Leon | Dunlop, Jason E. | Choy, S. C. (Satish C.) | Goonan, Peter
The risk of chemicals for ecological communities is often forecast with species sensitivity distributions (SSDs) which are used to predict the concentration which will protect p% of species (PCₚ value). However, at the PCₚ value, species richness in nature would not necessary be p% less than at uncontaminated sites. The definition of species richness inherent to SSDs (contaminant category richness) contrasts with species richness typically measured in most field studies (point richness). We determine, for salinity in eastern Australia, whether these definitions of stream macroinvertebrate species richness are commensurable. There were strong relationships (r²≥0.87) between mean point species, family and Ephemeroptera, Trichoptera and Plecoptera species richness and their respective contamination category richness. Despite differences in the definition of richness used by SSDs and field biomonitoring, their results in terms of relative species loss from salinity in south-east Australia are similar. We conclude that in our system both definitions are commensurable.
اظهر المزيد [+] اقل [-]The definition of species richness used by species sensitivity distributions approximates observed effects of salinity on stream macroinvertebrates النص الكامل
2010
Kefford, BJ | Marchant, R | Schaefer, RB | Metzeling, L | Dunlop, JE | Choy, SC | Goonan, P