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Sequestration of organochlorine pesticides in soils of distinct organic carbon content Full text
2011
Zhang, Na | Yang, Yu | Tao, Shu | Liu, Yan | Shi, Ke-Lu
In the present study, five soil samples with organic carbon contents ranging from 0.23% to 7.1% and aged with technical dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) for 15 months were incubated in a sealed chamber to investigate the dynamic changes of the OCP residues. The residues in the soils decreased over the incubation period and finally reached a plateau. Regression analysis showed that degradable fractions of OCPs were negatively correlated with soil organic carbon (SOC) except for α-HCH, while no correlation was found between degradation rate and SOC, which demonstrated that SOC content determines the OCP sequestration fraction in soil. Analysis of the ratio of DDT and its primary metabolites showed that, since it depends on differential sequestration among them, magnitude of (p,p′-DDE + p,p′-DDD)/p,p′-DDT is not a reliable criterion for the identification of new DDT sources.
Show more [+] Less [-]Transport of polycyclic aromatic hydrocarbons in highly vulnerable karst systems Full text
2011
Schwarz, Kerstin | Gocht, Tilman | Grathwohl, Peter
Fluxes of polycyclic aromatic hydrocarbons (PAHs) were investigated along the route of transport in a south German karst system. Atmospheric deposition, seepage water in caves and spring water at the outlet of the catchment were monitored continuously over 1.5 years allowing the establishment of an input/output mass balance at the catchment scale. The results reveal that, even in the highly vulnerable karst catchment, PAHs are effectively retained in the soils. Only during high discharge events, such as snowmelt in spring, increasing PAH concentrations at the outlet of the catchment indicates a mobilization of the pollutants. These events are typically correlated with increasing particle concentrations. Based on our results, we conclude that particle-facilitated transport is the dominating cause of PAH mobilization. In summary, PAHs accumulate over time in soils and only occasionally high discharge events cause a short concentration pulse to be flushed through the karst system.
Show more [+] Less [-]Responses of evergreen and deciduous Quercus species to enhanced ozone levels Full text
2011
Calatayud, Vicent | Cerveró, Júlia | Calvo, Esperanza | García Breijo, Francisco José | Reig-Armiñana, José | Sanz, María José
Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD₁.₆) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels.
Show more [+] Less [-]Combined effects of titanium dioxide and humic acid on the bioaccumulation of cadmium in Zebrafish Full text
2011
Hu, Xialin | Chen, Qiqing | Jiang, Lei | Yu, Zhenyang | Jiang, Danlie | Yin, Daqiang
The combined effects of titanium dioxide (TiO₂) nanoparticles and humic acid (HA) on the bioaccumulation of cadmium (Cd) in Zebrafish were investigated. Experimental data on the equilibrium Cd bioaccumulation suggest that only the dissolved Cd effectively contributed to Cd bioaccumulation in HA solutions whereas both the dissolved and TiO₂ associated Cd were accumulated in TiO₂ or the mixture of HA and TiO₂ solutions, due likely to the additional intestine uptake of the TiO₂-bound Cd. The equilibrium Cd bioaccumulation in the mixed system was comparable to that in the corresponding HA solutions, and significantly lower than that in the corresponding TiO₂ solutions (n = 3, p < 0.05). The presence of either HA or TiO₂ (5–20 mg L⁻¹) in water slightly increased the uptake rate constants of Cd bioaccumulation whereas combining HA and TiO₂ reduced the uptake rate constants.
Show more [+] Less [-]An urban boreal lake basin as a source of CO₂ and CH₄ Full text
2011
López Bellido, Jessica | Peltomaa, Elina | Ojala, Anne
Up to now, carbon gas fluxes from urban lakes in the boreal zone have seldom been studied. In summer 2005 we investigated fluxes from an urban boreal lake basin in southern Finland with long history of eutrophication and anoxia. Hypolimnetic CO₂ and CH₄ concentrations were high compared to other boreal lakes. During the open-water period, the lake basin acted as a source of CO₂ and CH₄ with fluxes of 2.10 mol m⁻² and 0.04 mol m⁻², respectively. Despite the high oxidation rate (83%), CH₄ flux was higher than in other lakes and CH₄ contributed 60% to Global Warming Potential. The ratio of carbon emission to accumulation was 4, i.e. emissions were an important route for carbon departure but less so than in rural lakes. Since the lake oxygen conditions affected nutrient availability, there was a positive feedback from hypolimnion to carbon uptake, which was reflected in gas concentrations.
Show more [+] Less [-]Reduction in uptake by rice and soybean of aromatic arsenicals from diphenylarsinic acid contaminated soil amended with activated charcoal Full text
2011
Arao, Tomohito | Maejima, Yuji | Baba, Koji
Activated charcoal (AC) amendment has been suggested as a promising method to immobilize organic contaminants in soil. We performed pot experiments with rice and soybean grown in agricultural soil polluted by aromatic arsenicals (AAs). The most abundant AA in rice grains and soybean seeds was methylphenylarsinic acid (MPAA). MPAA concentration in rice grains was significantly reduced to 2% and 3% in 0.2% AC treated soil compared to untreated soil in the first year of rice cultivation. In the second year, MPAA concentration in rice grains was significantly reduced to 15% in 0.2% AC treated soil compared to untreated soil. MPAA concentration in soybean seeds was significantly reduced to 44% in 0.2% AC treated soil compared to untreated soil. AC amendment was effective in reducing AAs in rice and soybean.
Show more [+] Less [-]Use of the MicroResp™ method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Marechal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Bérard, Annette
Use of the MicroResp™ method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Marechal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Bérard, Annette
Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroResp™ technique, in a pollution-induced community tolerance approach. The results show that MicroResp™ can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroResp™ was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river.
Show more [+] Less [-]Use of the MicroResp method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Marechal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Berard, Annette, A. | Structures et propriétés d'architectures moléculaire (SPRAM - UMR 5819) ; Institut Nanosciences et Cryogénie (INAC) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL) ; Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]) | Milieux aquatiques, écologie et pollutions (UR MALY) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | 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) | Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes (EMMAH) ; Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | International audience | A modified MicroRespÔ technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community. a b s t r a c t Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroRespÔ technique, in a pollution-induced community tolerance approach. The results show that MicroRespÔ can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroRespÔ was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river.
Show more [+] Less [-]Use of the MicroResp™ method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili , Ahmed (Institut National de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture, Lyon cedex 09(France). UR MAEP) | Maréchal , Marjorie (Institut National de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture, Lyon cedex 09(France). UR MAEP) | Montuelle , Bernard (Institut National de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture, Lyon cedex 09(France). UR MAEP) | Volat , Bernadette (Institut National de Recherche en Sciences et Technologies pour l'Environnement et l'Agriculture, Lyon cedex 09(France). UR MAEP) | Dorigo , Ursula (INRA , Thonon-Les-Bains (France). UMR 0042 Centre Alpin de Recherche sur les Réseaux Trophiques des Ecosystèmes limniques) | Berard , Annette (INRA , Avignon (France). UMR 1114 Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes )
Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroResp™ technique, in a pollution-induced community tolerance approach. The results show that MicroResp™ can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroResp™ was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river. A modified MicroResp™ technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community
Show more [+] Less [-]Use of the MicroResp (TM) method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Maréchal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Berard, Annette
Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroRes (TM) technique, in a pollution-induced community tolerance approach. The results show that MicroRes (TM) can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroRes (TM) was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river. A modified MicroRes (TM) technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community.
Show more [+] Less [-]Use of the MicroResp (TM) method to assess pollution-induced community tolerance to metals for lotic biofilms Full text
2011
Tlili, Ahmed | Maréchal, Marjorie | Montuelle, Bernard | Volat, Bernadette | Dorigo, Ursula | Berard, Annette
Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroRes (TM) technique, in a pollution-induced community tolerance approach. The results show that MicroRes (TM) can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroRes (TM) was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river. A modified MicroRes (TM) technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community.
Show more [+] Less [-]Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils Full text
2011
Gomez-Eyles, Jose L. | Collins, Chris D. | Hodson, Mark E.
Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils Full text
2011
Gomez-Eyles, Jose L. | Collins, Chris D. | Hodson, Mark E.
Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability.
Show more [+] Less [-]Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils Full text
2011
Gomez-Eyles, J L | Collins, Christopher David | Hodson, Mark Edward
Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability.
Show more [+] Less [-]Arsenic distribution in soils and plants of an arsenic impacted former mining area Full text
2011
Otones, V. | Álvarez-Ayuso, E. | García-Sánchez, A. | Santa Regina, I. | Murciego, A.
A mining area affected by the abandoned exploitation of an arsenical tungsten deposit was studied in order to assess its arsenic pollution level and the feasibility of native plants for being used in phytoremediation approaches. Soil and plant samples were collected at different distances from the polluting sources and analysed for their As content and distribution. Critical soil total concentrations of As were found, with values in the range 70–5330mgkg⁻¹ in the uppermost layer. The plant community develops As tolerance by exclusion strategies. Of the plant species growing in the most polluted site, the shrubs Salix atrocinerea Brot. and Genista scorpius (L.) DC. exhibit the lowest bioaccumulation factor (BF) values for their aerial parts, suggesting their suitability to be used with revegetation purposes. The species Scirpus holoschoenus L. highlights for its important potential to stabilise As at root level, accumulating As contents up to 3164mgkg⁻¹.
Show more [+] Less [-]Hydrocarbon degradation, plant colonization and gene expression of alkane degradation genes by endophytic Enterobacter ludwigii strains Full text
2011
Yousaf, Sohail | Afzal, Muhammad | Reichenauer, Thomas G. | Brady, Carrie L. | Sessitsch, Angela
Hydrocarbon degradation, plant colonization and gene expression of alkane degradation genes by endophytic Enterobacter ludwigii strains Full text
2011
Yousaf, Sohail | Afzal, Muhammad | Reichenauer, Thomas G. | Brady, Carrie L. | Sessitsch, Angela
The genus Enterobacter comprises a range of beneficial plant-associated bacteria showing plant growth promotion. Enterobacter ludwigii belongs to the Enterobacter cloacae complex and has been reported to include human pathogens but also plant-associated strains with plant beneficial capacities. To assess the role of Enterobacter endophytes in hydrocarbon degradation, plant colonization, abundance and expression of CYP153 genes in different plant compartments, three plant species (Italian ryegrass, birdsfoot trefoil and alfalfa) were grown in sterile soil spiked with 1% diesel and inoculated with three endophytic E. ludwigii strains. Results showed that all strains were capable of hydrocarbon degradation and efficiently colonized the rhizosphere and plant interior. Two strains, ISI10-3 and BRI10-9, showed highest degradation rates of diesel fuel up to 68% and performed best in combination with Italian ryegrass and alfalfa. All strains expressed the CYP153 gene in all plant compartments, indicating an active role in degradation of diesel in association with plants.
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