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Cai Chao – One of the best experts on this subject based on the ideXlab platform.
the effects of sewage sludge and sewage sludge biochar on pahs and potentially toxic element Bioaccumulation in cucumis sativa lChemosphere, 2014Co-Authors: Muhammad Waqas, Sardar Khan, Huang Qing, Brian J Reid, Cai ChaoAbstract:
Abstract The presence of contaminants such as polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs), including As, Cd, Cu, Pb and Zn, restricts the application of sewage sludge (SS) to agricultural land. This research established that the conversion of SS to SS biochar (SSBC) significantly ( p ⩽ 0.01) decreased PAH and available PTE concentrations. Once added to soil both SS and SSBC significantly (p ⩽ 0.05) decrease PAH availability. Bioaccumulation of PAHs into Cucumis sativa L. was reduced by both SSBC (44–57%) and (to a lesser extent 20–36%) by SS. Following addition to soil SSBC significantly ( p ⩽ 0.05) reduced available PTEs (except Cd), while SS significantly ( p ⩽ 0.05) increased PTE availability. As a consequence SSBC significantly ( p ⩽ 0.05) reduced PTE Bioaccumulation (except Cd and Zn), while SS increased PTE Bioaccumulation. These results suggest SSBC to be a candidate for soil amendment that offers advantages over SS in terms of PAH/PTE Bioaccumulation mitigation.
J.d. Lebrun – One of the best experts on this subject based on the ideXlab platform.
Comparison in waterborne Cu, Ni and Pb Bioaccumulation kinetics between different gammarid species and populations: Natural variability and influence of metal exposure historyAquatic Toxicology, 2017Co-Authors: N. Urien, E. Uher, A. Farfarana, A. Chaumot, L.c. Fechner, O. Geffard, J.d. LebrunAbstract:
Kinetic parameters (uptake from solution and elimination rate constants) of Cu, Ni and Pb Bioaccumulation were determined from two Gammarus pulex and three Gammarus fossrum wild populations collected from reference sites throughout France in order to assess the inter-species and the natural inter-population variability of metal Bioaccumulation kinetics in that sentinel organism. For that, each population was independently exposed for seven days to either 2.5 μg L−1 Cu (39.3 nM), 40 μg L−1 Ni (681 nM) or 10 μg L−1 Pb (48.3 nM) in laboratory controlled conditions, and then placed in unexposed microcosms for a 7-day depuration period. In the same way, the possible influence of metal exposure history on subsequent metal Bioaccumulation kinetics was addressed by collecting wild gammarids from three populations inhabiting stations contaminated either by Cd, Pb or both Pb and Ni (named pre-exposed thereafter). In these pre-exposed organisms, assessment of any changes in metal Bioaccumulation kinetics was achieved by comparison with the natural variability of kinetic parameters defined from reference populations. Results showed that in all studied populations (reference and pre-exposed) no significant Cu Bioaccumulation was observed at the exposure concentration of 2.5 μg L−1. Concerning the reference populations, no significant differences in Ni and Pb Bioaccumulation kinetics between the two species (G. pulex and G. fossarum) was observed allowing us to consider all the five reference populations to determine the inter-population natural variability, which was found to be relatively low (kinetic parameters determined for each population remained within a factor of 2 of the minimum and maximum values). Organisms from the population exhibiting a Pb exposure history presented reduced Ni uptake and elimination rate constants, whereas no influence on Ni kinetic parameters was observed in organisms from the population exhibiting an exposure history to both Ni and Pb. Furthermore Pb Bioaccumulation kinetics were unaffected whatever the condition of pre-exposure in natural environment. Finally, these results highlight the complexity of confounding factors, such as metal exposure history, that influence metal Bioaccumulation processes and showed that pre-exposure to one metal can cause changes in the Bioaccumulation kinetics of other metals. These results also address the question of the underlying mechanisms developed by organisms to cope with metal contamination.
Contribution of aqueous and dietary uptakes to lead (Pb) Bioaccumulation in Gammarus pulex: From multipathway modeling to in situ validationEcotoxicology and Environmental Safety, 2016Co-Authors: R. Hadji, N. Urien, E. Uher, L.c. Fechner, J.d. LebrunAbstract:
Abstract Although dynamic approaches are nowadays used increasingly to describe metal Bioaccumulation in aquatic organisms, the validation of such laboratory-derived modeling is rarely assessed under environmental conditions. Furthermore, information on Bioaccumulation kinetics of Pb and the significance of its uptake by dietary route is scarce in freshwater species. This study aims at modeling aqueous and dietary uptakes of Pb in the litter-degrader Gammarus pulex and assessing the predictive quality of multipathway modeling from in situ Bioaccumulation data. In microcosms, G. pulex were exposed to environmentally realistic concentrations of Pb (from 0.1 to 10 µg/L) in the presence of Pb-contaminated poplar leaves, which were enclosed or not in a net to distinguish aqueous and dietary uptakes. Results show that water and food both constitute contamination sources for gammarids. Establishing biodynamic parameters involved in Pb aqueous and dietary uptake and elimination rates enabled to construct a multipathway model to describe Pb Bioaccumulation in gammarids. This laboratory-derived model successfully predicted Bioaccumulation measured in native populations of G. pulex collected in situ when local litter was used as dietary exposure source. This study demonstrates not only the suitable applicability of biodynamic parameters for predicting Pb Bioaccumulation but also the necessity of taking dietary uptake into account for a better interpretation of the gammarids’ contamination in natural conditions.
Contrasting abilities of metal Bioaccumulation in Gammarus populations with different exposure histories, 2015Co-Authors: N. Urien, J.d. Lebrun, A. Farfarana, A. Chaumot, L.c. Fechner, Olivier GeffardAbstract:
Kinetic models are used to link metal exposure to metal contamination in aquatic organisms and enable also the prediction of metal Bioaccumulation. Kinetic models are characterised by kinetic parameters (uptake and elimination rate constants) which can be determined in controlled conditions. “Global” kinetic parameters for Cd, Pb and Ni have been established in five naïve populations of gammarids. Gammarids can, however, live in rivers exhibiting metal contamination to which organisms may adapt physiologically. Adaptation can result in the modulation of Bioaccumulation abilities i.e. kinetic parameters. This may limit the environmental relevance of kinetic models and the reliability of Bioaccumulation predictions. The aim of thsi study was to assess the Bioaccumulation abilities of metals in gammarids chronically exposed to metals in situ by (i) determining the kinetic parameters describing Cd, Pb and Ni Bioaccumulation in populations of gammarids chronically exposed to metals in situ, (ii) comparing the kinetic parameters with “global” kinetic parameters already determined in five naïve populations of gammarids.
Marianna Taffi – One of the best experts on this subject based on the ideXlab platform.
Bioaccumulation modelling and sensitivity analysis for discovering key players in contaminated food webs the case study of pcbs in the adriatic seaEcological Modelling, 2015Co-Authors: Marianna Taffi, Nicola Paoletti, Sandra Pucciarelli, Mauro MariniAbstract:
Modelling Bioaccumulation processes at the food web level is the main step to analyse the effects of pollutants at the global ecosystem level. A crucial question is understanding which species play a key role in the trophic transfer of contaminants to disclose the contribution of feeding linkages and the importance of trophic dependencies in Bioaccumulation dynamics. In this work we present a computational framework to model the Bioaccumulation of organic chemicals in aquatic food webs, and to discover key species in polluted ecosystems. As a result, we reconstruct the first PCBs Bioaccumulation model of the Adriatic food web, estimated after an extensive review of published concentration data. We define a novel index aimed to identify the key species in contaminated networks, sensitivity centrality, and based on sensitivity analysis. The index is computed from a dynamic ODE model parametrised from the estimated PCBs Bioaccumulation model and compared with a set of established trophic indices of centrality. Results evidence the occurrence of PCBs biomagnification in the Adriatic food web, and highlight the dependence of Bioaccumulation on trophic dynamics and external factors like fishing activity. We demonstrate the effectiveness of the introduced sensitivity centrality in identifying the set of species with the highest impact on the total contaminant flows and on the efficiency of contaminant transport within the food web.