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Persistent organic pollutants in four bivalve species from Svalbard waters Full text
2012
Vieweg, Ireen | Hop, Haakon | Brey, Thomas | Huber, Sandra | Ambrose, William G., Jr | Locke V, William L. | Gabrielsen, Geir W.
Persistent organic pollutants in four bivalve species from Svalbard waters Full text
2012
Vieweg, Ireen | Hop, Haakon | Brey, Thomas | Huber, Sandra | Ambrose, William G., Jr | Locke V, William L. | Gabrielsen, Geir W.
Organochlorine compounds (OC) were determined in Arctic bivalves (Mya truncata, Serripes groenlandicus, Hiatella arctica and Chlamys islandica) from Svalbard with regard to differences in geographic location, species and variations related to their size and age. Higher chlorinated polychlorinated biphenyls (PCB 101–PCB 194), chlordanes and α-hexachlorocyclohexane (α-HCH) were consistently detected in the bivalves and PCBs dominated the OC load in the organisms. OC concentrations were highest in Mya truncata and the lowest in Serripes groenlandicus. Species-specific OC levels were likely related to differences in the species’ food source, as indicated by the δ¹³C results, rather than size and age. Higher OC concentrations were observed in bivalves from Kongsfjorden compared to the northern sampling locations Liefdefjorden and Sjuøyane. The spatial differences might be related to different water masses influencing Kongsfjorden (Atlantic) and the northern locations (Arctic), with differing phytoplankton bloom situations.
Show more [+] Less [-]Persistent organic pollutants in four bivalve species from Svalbard waters Full text
2012
Vieweg, Ireen | Hop, Haakon | Brey, Thomas | Huber, Sandra | Ambrose, William G. | Locke, William L.
Organochlorine compounds (OC) were determined in Arctic bivalves (Mya truncata, Serripes groenlandicus, Hiatella arctica, Chlamys islandica) from Svalbard with regard to differences in geographic location, species and variations related to their size and age. Higher chlorinated polychlorinated biphenyls (PCB 101- PCB 194), chlordanes and α-hexachlorocyclohexane (α-HCH) were consistently detected in the bivalves and PCBs dominated the OC load in the organisms. OC concentrations were highest in Mya truncata and the lowest in Serripes groenlandicus. Species-specific OC levels were likely related to differences in the species' food source, as indicated by the δ13C results, rather than size and age. Higher OC concentrations were observed in bivalves from Kongsfjorden compared to the northern sampling locations Liefdefjorden and Sjuøyane. The spatial differences might be related to different water masses influencing Kongsfjorden (Atlantic) and the northern locations (Arctic), with differing phytoplankton bloom situations.
Show more [+] Less [-](Table 3) Organochlorine compounds in tissue samples of four bivalve species from Svalbard in July 2009 Full text
2012
Vieweg, Ireen | Hop, Haakon | Brey, Thomas | Huber, Sandra | Ambrose, William G Jr | Locke, William L | Gabrielsen, Geir W
(Table 1) Stable carbon and nitrogen isotopes in tissue samples of four bivalve species from Svalbard in July 2009 Full text
2012
Vieweg, Ireen | Hop, Haakon | Brey, Thomas | Huber, Sandra | Ambrose, William G Jr | Locke, William L | Gabrielsen, Geir W
(Table 2) Shell lengths of four bivalve species from Svalbard in July 2009 Full text
2012
Vieweg, Ireen | Hop, Haakon | Brey, Thomas | Huber, Sandra | Ambrose, William G Jr | Locke, William L | Gabrielsen, Geir W
Stable isotopic ratios, shell lengths and organochlorine compounds in four bivalve species collected in July 2009 around Svalbard Full text
2012
Vieweg, Ireen | Hop, Haakon | Brey, Thomas | Huber, Sandra | Ambrose, William G Jr | Locke, William L | Gabrielsen, Geir W
Organochlorine compounds (OC) were determined in Arctic bivalves (Mya truncata, Serripes groenlan-dicus, Hiatella arctica and Chlamys islandica) from Svalbard with regard to differences in geographic location, species and variations related to their size and age. Higher chlorinated polychlorinated biphenyls (PCB 101-PCB 194), chlordanes and alpha-hexachlorocyclohexane (alpha-HCH) were consistently detected in the bivalves and PCBs dominated the OC load in the organisms. OC concentrations were highest in Mya truncata and the lowest in Serripes groenlandicus. Species-specific OC levels were likely related to differences in the species' food source, as indicated by the d13C results, rather than size and age. Higher OC concentrations were observed in bivalves from Kongsfjorden compared to the northern sampling locations Liefdefjorden and Sjuoyane. The spatial differences might be related to different water masses influencing Kongsfjorden (Atlantic) and the northern locations (Arctic), with differing phytoplankton bloom situations.
Show more [+] Less [-]The effect of airborne particles and weather conditions on pediatric respiratory infections in Cordoba, Argentine Full text
2012
The effect of airborne particles and weather conditions on pediatric respiratory infections in Cordoba, Argentine Full text
2012
We studied the effect of estimated PM₁₀ on respiratory infections in children from Cordoba, Argentine as well as the influence of weather factors, socio-economic conditions and education. We analyzed upper and lower respiratory infections and applied a time-series analysis with a quasi-Poisson distribution link function. To control for seasonally varying factors we fitted cubic smoothing splines of date. We also examined community-specific parameters and differences in susceptibility by sex. We found a significant association between particles and respiratory infections. This relationship was affected by mean temperature, atmospheric pressure and wind speed. These effects were stronger in fall, winter and spring for upper respiratory infections while for lower respiratory infections the association was significant only during spring. Low socio-economic conditions and low education levels increased the risk of respiratory infections. These findings add useful information to understand the influence of airborne particles on children health in developing countries.
Show more [+] Less [-]The effect of airborne particles and weather conditions on pediatric respiratory infections in Cordoba, Argentine Full text
2012
Amarillo, Ana Carolina | Carreras, Hebe Alejandra
We studied the effect of estimated PM10 on respiratory infections in children from Cordoba, Argentine as well as the influence of weather factors, socio-economic conditions and education. We analyzed upper and lower respiratory infections and applied a time-series analysis with a quasi-Poisson distribution link function. To control for seasonally varying factors we fitted cubic smoothing splines of date. We also examined community-specific parameters and differences in susceptibility by sex. We found a significant association between particles and respiratory infections. This relationship was affected by mean temperature, atmospheric pressure and wind speed. These effects were stronger in fall, winter and spring for upper respiratory infections while for lower respiratory infections the association was significant only during spring. Low socio-economic conditions and low education levels increased the risk of respiratory infections. These findings add useful information to understand the influence of airborne particles on children health in developing countries. | Fil: Amarillo, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas Fisicas y Naturales. Departamento de Quimica; Argentina | Fil: Carreras, Hebe Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas Fisicas y Naturales. Departamento de Quimica; Argentina
Show more [+] Less [-]Polychlorinated naphthalenes (PCNs) in sub-Arctic and Arctic marine mammals, 1986–2009 Full text
2012
Rotander, Anna | van Bavel, Bert | Riget, Frank | Auðunsson, Guðjón Atli | Polder, Anuschka | Gabrielsen, Geir Wing | Víkingsson, Gísli | Mikkelsen, Bjarni | Dam, Maria
Polychlorinated naphthalenes (PCNs) in sub-Arctic and Arctic marine mammals, 1986–2009 Full text
2012
Rotander, Anna | van Bavel, Bert | Riget, Frank | Auðunsson, Guðjón Atli | Polder, Anuschka | Gabrielsen, Geir Wing | Víkingsson, Gísli | Mikkelsen, Bjarni | Dam, Maria
A selection of PCN congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbour porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986–2009). A large geographical area of the North Atlantic and Arctic areas was covered. PCN congeners 48, 52, 53, 66 and 69 were found in the blubber samples between 0.03 and 5.9 ng/g lw. Also PCBs were analyzed in minke whales and fin whales from Iceland and the total PCN content accounted for 0.2% or less of the total non-planar PCB content. No statistically significant trend in contaminant levels could be established for the studied areas. However, in all species except minke whales caught off Norway the lowest ∑PCN concentrations were found in samples from the latest sampling period.
Show more [+] Less [-](Table 2) Concentrations of polychlorinated naphthalene congeners in blubber samples from whales, seals and porpoises between 1986-2009 Full text
2012
Rotander, Anna | van Bavel, Bert | Rigét, Frank F | Auðunsson, Guðjón Atli | Polder, Anuschka | Gabrielsen, Geir W | Víkingsson, Gísli | Mikkelsen, Bjarni | Dam, Maria
A selection of PCN congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbour porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic whitesided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). A large geographical area of the North Atlantic and Arctic areas was covered. PCN congeners 48, 52, 53, 66 and 69 were found in the blubber samples between 0.03 and 5.9 ng/g lw. Also PCBs were analyzed in minke whales and fin whales from Iceland and the total PCN content accounted for 0.2% or less of the total non-planar PCB content. No statistically significant trend in contaminant levels could be established for the studied areas. However, in all species except minke whales caught off Norway the lowest Sum PCN concentrations were found in samples from the latest sampling period.
Show more [+] Less [-]Transformation of PBDE mixtures during sediment transport and resuspension in marine environments (Gulf of Lion, NW Mediterranean Sea) Full text
2012
Salvadó, Joan A. | Grimalt, Joan O. | López, Jordi F. | Durrieu de Madron, Xavier | Heussner, Serge | Canals, M. (Miquel)
Transformation of PBDE mixtures during sediment transport and resuspension in marine environments (Gulf of Lion, NW Mediterranean Sea) Full text
2012
Salvadó, Joan A. | Grimalt, Joan O. | López, Jordi F. | Durrieu de Madron, Xavier | Heussner, Serge | Canals, M. (Miquel)
Polybromodiphenyl ethers (PBDEs) in superficial sediments from the Gulf of Lion were studied. They were largely predominated by BDE 209 (98.7% of all PBDEs) indicating that the main source of these pollutants was the commercial mixture deca-BDE. This compound and the less brominated BDE exhibited a southwestward decreasing concentration gradient following the dominant marine currents and bottom relief, e.g. the Mud Belt, the submarine canyons and the Open Continental Slope. All PBDEs exhibited statistically significant correlations confirming the common origin. However, a progressive transformation of the dumped BDE 209 was identified showing a depletion paralleled by increases of the less brominated BDEs (from 8.6% to 22%). These less brominated compounds were accumulated at about 100–140km away from the Rhone prodelta, e.g. at the end of the submarine canyons, evidencing that these transformation compounds can be accumulated at long distances from the dumping sites in the marine system.
Show more [+] Less [-]Transformation of PBDE mixtures during sediment transport and resuspension in marine environments (Gulf of Lion, NW Mediterranean Sea) Full text
2012
Salvadó, Joan A. | Grimalt, Joan O. | López, Jordi F. | Durrieu de Madron, Xavier | Heussner, Serge | Canals, Miquel
Polybromodiphenyl ethers (PBDEs) in superficial sediments from the Gulf of Lion were studied. They were largely predominated by BDE 209 (98.7% of all PBDEs) indicating that the main source of these pollutants was the commercial mixture deca-BDE. This compound and the less brominated BDE exhibited a southwestward decreasing concentration gradient following the dominant marine currents and bottom relief, e.g. the Mud Belt, the submarine canyons and the Open Continental Slope. All PBDEs exhibited statistically significant correlations confirming the common origin. However, a progressive transformation of the dumped BDE 209 was identified showing a depletion paralleled by increases of the less brominated BDEs (from 8.6% to 22%). These less brominated compounds were accumulated at about 100–140 km away from the Rhone prodelta, e.g. at the end of the submarine canyons, evidencing that these transformation compounds can be accumulated at long distances from the dumping sites in the marine system. | Highlights ► Polybromodiphenyl ethers are associated to organic carbon in marine sediments. ► PBDEs in marine sediments can accumulate further away than 140 km from the spill site. ► BDE-209 in marine sediments generate congeners found in banned commercial mixtures. ► BDE-209 in marine sediments generates new congeners not found in commercial mixtures. ► Submarine canyons channel PBDEs from the continental platform to the deep shelf. | Financial support from the GRACCIE consolider project (CSD2007-00067) is acknowledged. This paper was also sponsored by research groups 2009SGR1178 and 2009SGR1305 from Generalitat de Catalunya. | Peer reviewed
Show more [+] Less [-]Toxicokinetic of benzo[a]pyrene and fipronil in female green frogs (Pelophylax kl. esculentus) Full text
2012
Reynaud, Stéphane | Worms, Isabelle A.M. | Veyrenc, Sylvie | Portier, Julien | Maitre, Anne | Miaud, Claude | Raveton, Muriel
Toxicokinetic of benzo[a]pyrene and fipronil in female green frogs (Pelophylax kl. esculentus) Full text
2012
Reynaud, Stéphane | Worms, Isabelle A.M. | Veyrenc, Sylvie | Portier, Julien | Maitre, Anne | Miaud, Claude | Raveton, Muriel
A general consensus that an increased logKₒw led to an increase in xenobiotic uptake and bioaccumulation is accepted. In this study we compared the toxicokinetics of two chemically different xenobiotics, i.e. benzo[a]pyrene and fipronil in female green frogs. Surprisingly, the uptake rates and the bioconcentration factors (BCF) of the two contaminants were not predicted by their logKₒw. The uptake rates obtained were of the same order of magnitude for the two contaminants and the BCFs measured for fipronil were about 3-fold higher than those obtained for benzo[a]pyrene. Fipronil appeared to be more recalcitrant than benzo[a]pyrene to detoxification processes leading to the accumulation of sulfone-fipronil especially in the ovaries. This phenomenon may explain reproductive influence of this contaminant described in other studies. Detoxification processes, including metabolism and the excretion of pollutants, are of importance when considering their persistence in aquatic organisms and trying to quantify their risks.
Show more [+] Less [-]Toxicokinetic of benzo[a]pyrene and fipronil in female green frogs (Pelophylax kl. esculentus) Full text
2012
Reynaud, Stéphane | Worms, Isabelle A.M. | Veyrenc, Sylvie | Portier, Julien | Maitre, Anne | Miaud, Claude | Raveton, Muriel | Laboratoire d'Ecologie Alpine (LECA) ; Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS) | École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL) | Centre Hospitalier Universitaire [CHU Grenoble] (CHUGA) | EPSP ; Techniques de l'Ingénierie Médicale et de la Complexité - Informatique, Mathématiques et Applications, Grenoble - UMR 5525 (TIMC-IMAG) ; Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Centre Hospitalier Universitaire [CHU Grenoble] (CHUGA) | Centre d’Ecologie Fonctionnelle et Evolutive (CEFE) ; Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [Occitanie])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)
International audience
Show more [+] Less [-]Updated stomatal flux and flux-effect models for wheat for quantifying effects of ozone on grain yield, grain mass and protein yield Full text
2012
Grünhage, Ludger | Pleijel, Håkan | Mills, Gina | Bender, Jürgen | Danielsson, Helena | Lehmann, Yvonne | Castell, Jean-Francois | Bethenod, Olivier
Updated stomatal flux and flux-effect models for wheat for quantifying effects of ozone on grain yield, grain mass and protein yield Full text
2012
Grünhage, Ludger | Pleijel, Håkan | Mills, Gina | Bender, Jürgen | Danielsson, Helena | Lehmann, Yvonne | Castell, Jean-Francois | Bethenod, Olivier
Field measurements and open-top chamber experiments using nine current European winter wheat cultivars provided a data set that was used to revise and improve the parameterisation of a stomatal conductance model for wheat, including a revised value for maximum stomatal conductance and new functions for phenology and soil moisture. For the calculation of stomatal conductance for ozone a diffusivity ratio between O₃ and H₂O in air of 0.663 was applied, based on a critical review of the literature. By applying the improved parameterisation for stomatal conductance, new flux-effect relationships for grain yield, grain mass and protein yield were developed for use in ozone risk assessments including effects on food security. An example of application of the flux model at the local scale in Germany shows that negative effects of ozone on wheat grain yield were likely each year and on protein yield in most years since the mid 1980s.
Show more [+] Less [-]Updated stomatal flux and flux-effect models for wheat for quantifying effects of ozone on grain yield, grain mass and protein yield Full text
2012
Grünhage, Ludger, L. | Pleijel, Hakan, H. | Mills, Gina, G. | Bender, Jürgen, J. | Danielsson, Helena, H. | Lehmann, Yvonne, Y. | Castell, Jean-François, J.-F. | Bethenod, Olivier, O. | Department of Plant Ecology ; Justus-Liebig-Universität Gießen = Justus Liebig University (JLU) | Department of Plant and Environmental Sciences ; Göteborgs Universitet = University of Gothenburg (GU) | Centre for Ecology and Hydrology [Bangor] (CEH) ; Natural Environment Research Council (NERC) | Institute of Biodiversity ; Johann Heinrich von Thünen-Institut = Thünen Institute | Environnement et Grandes Cultures (EGC) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Swedish Environment Protection Agency; Defra [AQ0810, AQ0816, AQ0601]; LRTAP Convention; NERC; French National Research Agency, ANR
Field measurements and open-top chamber experiments using nine current European winter wheat cultivars provided a data set that was used to revise and improve the parameterisation of a stomatal conductance model for wheat, including a revised value for maximum stomatal conductance and new functions for phenology and soil moisture. For the calculation of stomatal conductance for ozone a diffusivity ratio between O(3) and H(2)O in air of 0.663 was applied, based on a critical review of the literature. By applying the improved parameterisation for stomatal conductance, new flux-effect relationships for grain yield, grain mass and protein yield were developed for use in ozone risk assessments including effects on food security. An example of application of the flux model at the local scale in Germany shows that negative effects of ozone on wheat grain yield were likely each year and on protein yield in most years since the mid 1980s.
Show more [+] Less [-]Updated stomatal flux and flux-effect models for wheat for quantifying effects of ozone on grain yield, grain mass and protein yield Full text
2012
Grünhage, Ludger, L. | Pleijel, Hakan, H. | Mills, Gina, G. | Bender, Jürgen, J. | Danielsson, Helena, H. | Lehmann, Yvonne, Y. | Castell, Jean-François, J.-F. | Bethenod, Olivier, O. | Department of Plant Ecology ; Justus-Liebig-Universität Gießen = Justus Liebig University (JLU) | Department of Plant and Environmental Sciences ; University of Gothenburg (GU) | Centre for Ecology and Hydrology [Bangor] (CEH) ; Natural Environment Research Council (NERC) | Institute of Biodiversity ; Johann Heinrich von Thünen-Institute | Environnement et Grandes Cultures (EGC) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Swedish Environment Protection Agency; Defra [AQ0810, AQ0816, AQ0601]; LRTAP Convention; NERC; French National Research Agency, ANR
Field measurements and open-top chamber experiments using nine current European winter wheat cultivars provided a data set that was used to revise and improve the parameterisation of a stomatal conductance model for wheat, including a revised value for maximum stomatal conductance and new functions for phenology and soil moisture. For the calculation of stomatal conductance for ozone a diffusivity ratio between O(3) and H(2)O in air of 0.663 was applied, based on a critical review of the literature. By applying the improved parameterisation for stomatal conductance, new flux-effect relationships for grain yield, grain mass and protein yield were developed for use in ozone risk assessments including effects on food security. An example of application of the flux model at the local scale in Germany shows that negative effects of ozone on wheat grain yield were likely each year and on protein yield in most years since the mid 1980s.
Show more [+] Less [-]Updated stomatal flux and flux-effect models for wheat for quantifying effects of ozone on grain yield, grain mass and protein yield Full text
2012
Grünhage, Ludger | Pleijel, Hakan | Mills, Gina | Bender, Jürgen | Danielsson, Helena | Lehmann, Yvonne | Castell, Jean-Francois | Bethenod, Olivier
The challenge of choosing environmental indicators of anthropogenic impacts in estuaries Full text
2012
Dafforn, Katherine A. | Simpson, Stuart L. | Kelaher, Brendan P. | Clark, Graeme F. | Komyakova, Valeriya | Wong, Chris K.C. | Johnston, Emma L.
The challenge of choosing environmental indicators of anthropogenic impacts in estuaries Full text
2012
Dafforn, Katherine A. | Simpson, Stuart L. | Kelaher, Brendan P. | Clark, Graeme F. | Komyakova, Valeriya | Wong, Chris K.C. | Johnston, Emma L.
Ecological assessments over large spatial scales require that anthropogenic impacts be distinguishable above natural variation, and that monitoring tools are implemented to maximise impact detection and minimise cost. For three heavily modified and four relatively ‘pristine’ estuaries (disturbance category), chemical indicators (metals and PAHs) of anthropogenic stress were measured in benthic sediments, suspended sediments and deployed oysters, together with other environmental variables. These were compared with infaunal and hard-substrate invertebrate communities. Univariate analyses were useful for comparing contaminant loads between different monitoring tools and identified the strongest relationships between benthic and suspended sediments. However, multivariate analyses were necessary to distinguish ecological response to anthropogenic stressors from environmental “noise” over a large spatial scale and to identify sites that were being impacted by contaminants. These analyses provide evidence that suspended sediments are a useful alternative monitoring tool to detect potential anthropogenic impacts on benthic (infaunal and hard-substrate) communities.
Show more [+] Less [-]The challenge of choosing environmental indicators of anthropogenic impacts in estuaries Full text
2011
Dafforn, KA | Simpson, SL | Kelaher, BP | Clark, GF | Komyakova, V | Wong, CKC | Johnston, EL
Ecological assessments over large spatial scales require that anthropogenic impacts be distinguishable above natural variation, and that monitoring tools are implemented to maximise impact detection and minimise cost. For three heavily modified and four relatively 'pristine' estuaries (disturbance category), chemical indicators (metals and PAHs) of anthropogenic stress were measured in benthic sediments, suspended sediments and deployed oysters, together with other environmental variables. These were compared with infaunal and hard-substrate invertebrate communities. Univariate analyses were useful for comparing contaminant loads between different monitoring tools and identified the strongest relationships between benthic and suspended sediments. However, multivariate analyses were necessary to distinguish ecological response to anthropogenic stressors from environmental "noise" over a large spatial scale and to identify sites that were being impacted by contaminants. These analyses provide evidence that suspended sediments are a useful alternative monitoring tool to detect potential anthropogenic impacts on benthic (infaunal and hard-substrate) communities. © 2011 Elsevier Ltd. All rights reserved.
Show more [+] Less [-]Quantitative identification of dynamic and static quenching of ofloxacin by dissolved organic matter using temperature-dependent kinetic approach Full text
2012
Pan, Bo | Liu, Ying | Xiao, Di | Wu, Fengchang | Wu, Min | Zhang, Di | Xing, Baoshan
Ofloxacin (OFL) was used as a model antibiotic and the quenching of OFL fluorescence by DOM was examined with an emphasis on temperature-dependent quenching kinetics. OFL fluorescence intensity was corrected for inner filter and temperature effects. The kinetics data were fitted well using a two-compartment pseudo first-order kinetics model. Three quenching compartments were identified using this model, namely, a very fast quenching compartment (q₀) and two pseudo first-order quenching compartments (q₁ + q₂). The q₀ values had a positive relationship with temperature, while (q₁ + q₂) were negatively related with temperature. In addition, OFL–DOM binding quantified by (q₁ + q₂) was consistent with binding result obtained from dialysis equilibrium system. We concluded that q₀ was resulted from dynamic quenching, while (q₁ + q₂) was attributed to static quenching. The dynamic quenching of OFL by DOM accounted for 30–90% to the overall quenching and thus was very significant.
Show more [+] Less [-]Interactions of ¹⁴C-labeled multi-walled carbon nanotubes with soil minerals in water Full text
2012
Zhang, Liwen | Petersen, Elijah J. | Zhang, Wen | Chen, Yongsheng | Cabrera, Miguel | Huang, Qingguo
Carbon nanotubes are often modified to be stable in the aqueous phase by adding extensive hydrophilic surface functional groups. The stability of such CNTs in water with soil or sediment is one critical factor controlling their environmental fate. We conducted a series of experiments to quantitatively assess the association between water dispersed multi-walled carbon nanotubes (MWCNTs) and three soil minerals (kaolinite, smectite, or shale) in aqueous solution under different sodium concentrations. ¹⁴C-labeling was used in these experiments to unambiguously quantify MWCNTs. The results showed that increasing ionic strength strongly promoted the removal of MWCNTs from aqueous phase. The removal tendency is inversely correlated with the soil minerals’ surface potential and directly correlated with their hydrophobicity. This removal can be interpreted by the extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory especially for kaolinite and smectite. Shale, which contains large and insoluble organic materials, sorbed MWCNTs the most strongly.
Show more [+] Less [-]The fractional patterns of polybrominated diphenyl ethers in the soil of the central Tibetan Plateau, China: The influence of soil components Full text
2012
Yuan, Guo-Li | Xie, Wei | Che, Xiao-Chao | Han, Peng | Liu, Chen | Wang, Gen-Hou
Sixteen soil samples were collected from the central Tibetan Plateau (CTP). The soil concentrations of polybrominated diphenyl ethers (PBDEs) in CTP were analyzed. The detected 42 congeners were divided into light, intermediate and heavy fractions. In addition to the various minerals, other soil properties were also characterized, including the content of soil organic carbon (SOC) and the particle size distribution. The clay content is positively related to the intermediate fraction of the PBDEs and negatively related to the light and heavy fractions. Similar correlations were observed for SOC and the fine-particle fraction (size < 2 μm). The coefficient of determination (r²) associated with a linear regression indicated that the clays were more highly correlated with the fractional pattern of the PBDEs than with the other properties, such as SOC and the fine-particle fraction. The values of r² between clays and three fractions of PBDEs are 0.70, 0.69 and 0.58.
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