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Assessing ecotoxicity and uptake of metals and metalloids in relation to two different earthworm species (Eiseina horterzsis and Lumbricus terrestris)
2013
Leveque, Thibaut | Capowiez, Yvan | Schreck, Eva | Mazzia, Christophe | Auffan, Mélanie | Foucault, Yann | Austruy, Annabelle
Due to diffuse atmospheric fallouts of process particles enriched by metals and metalloids, polluted soils concern large areas at the global scale. Useful tools to assess ecotoxicity induced by these polluted soils are therefore needed. Earthworms are currently used as biotest, however the influence of specie and earthworm behaviour, soil characteristics are poorly highlighted. Our aim was therefore to assess the toxicity of various polluted soils with process particles enriches by metals and metalloids (Pb, Cd, Cu, Zn, As and Sb) collected from a lead recycling facility on two earthworm species belonging to different ecological types and thus likely to have contrasted behavioural responses (Eiseina hortensis and Lumbricus terrestris). The combination of behavioural factors measurements (cast production and biomass) and physicochemical parameters such as metal absorption, bioaccumulation by earthworms and their localization in invertebrate tissues provided a valuable indication of pollutant bioavailability and ecotoxicity. Soil characteristics influenced ecotoxicity and metal uptake by earthworms, as well as their soil bioturbation.
Show more [+] Less [-]Variation patterns in individual fish responses to chemical stress among estuaries, seasons and genders: the case of the European flounder (Platichthys flesus) in the Bay of Biscay
2013
Laroche, Jean | Gauthier, Olivier | Quiniou, Louis | Devaux, Alain | Bony, Sylvie | Evrard, Estérine | Cachot, Jérôme | Cherel, Yan | Larcher, Thibaut | Riso, Ricardo | Pichereau, Vianney | Devier, Marie-Hélène | Budzinski, Hélène
The objective was to describe and model varia- tion patterns in individual fish responses to contaminants among estuaries, season and gender. Two hundred twenty- seven adult European flounders were collected in two sea- sons (winter and summer) in four estuaries along the Bay of Biscay (South West France), focusing on a pristine system (the Ster), vs. three estuaries displaying contrasted levels of contaminants (the Vilaine, Loire and Gironde). Twenty-three variables were measured by fish, considering the load of contaminants (liver metals, liver and muscle persistent organic pollutants, muscle polycyclic aromatic hydrocar- bons); the gene expression (Cyt C oxydase, ATPase, BHMT, Cyt P450 1A1, ferritin); the blood genotoxicity (Comet test); and liver histology (foci of cellular alteration–tumour, steatosis, inflammation, abnormal glycogen storage). Ca- nonical redundancy analysis (RDA) was used to model these variables using gender, season and estuary of origin as explanatory variables. The results underlined the homo- geneity of fish responses within the pristine site (Ster) and more important seasonal variability within the three contam- inated systems. The complete model RDA was significant and explained 35 % of total variance. Estuary and season respectively explained 30 and 5 % of the total independent variation components, whilst gender was not a significant factor. The first axis of the RDA explains nearly 27 % of the total variance and mostly represents a gradient of contami- nation. The links between the load of contaminants, the expression of several genes and the biomarkers were ana- lysed considering different levels of chemical stress and a possible multi-stress, particularly in the Vilaine estuary.
Show more [+] Less [-]The dynamics of environmental concern and the evolution of pollution
2013
Bezin, Emeline
Nous développons un modèle à générations emboîtées dans lequel l’évolution de la pollutionet la formation de la préoccupation environnementale sont endogènes. D’un côté, despersonnes concernées de façon hétérogène par les questions environnementales participentvolontairement à la dépollution. D’un autre côté, la transmission des attitudes vis-à-vis del’environnement résulte d’un choix économique qui dépend lui-même de la pollution. Lemodèle prédit que la proportion à long terme d’individus préoccupés par l’environnement seraforte dans tous les cas. Cependant, selon la nature de la technologie qui génère la pollution, latransition d’une société peu préoccupée par l’environnement vers une société fortementpréoccupée par l’environnement s’accompagne de deux effets différents sur le niveau depollution à long terme. Si la technologie est « propre », on aboutit à un niveau d’équilibrestable de pollution. A l’inverse, si elle est « sale », la pollution connaît une croissanceillimitée qui finit par causer un désastre environnemental. Ce résultat reproduit les faitsstylisés observés quant à l’évolution conjointe de la préoccupation environnementale et lapollution dans les pays en développement. Dans le deuxième cas, nous montrons que destransferts intergénérationnels de la génération âgée vers la génération active jeune rétablissentla possibilité d’atteindre un état stationnaire de pollution. | We develop an overlapping generations model within which the evolution of pollution and theformation of environmental concern are endogenous. On the one hand, peopleheterogeneously concerned with environmental issues contribute to pollution which is apublic bad. On the other hand, the transmission of environmental attitudes is the result ofsome economic choice which is affected by pollution. The model predicts that the long runproportion of environmentally concerned individuals will always be high. Though, dependingon the pollution-generating technology, the transition from a low-environmentally concernedsociety to a high-environmentally concerned one is accompanied by two different outcomesregarding the long run level of pollution. If the technology is “clean”, there is a stable steadystate level of pollution. However, if it is “dirty”, pollution experiences an unlimited growthwhich eventually causes an environmental disaster. This result captures some stylized factsregarding the joint evolution of environmental concern and pollution in developing nations. Inthe latter case, we show that intergenerational transfers from the older generation to the youngworking one restore the possibility to reach a stationary level of pollution.
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