Structural and functional responses of a benthic macroinvertebrate assemblage to pulses of the insecticide imidacloprid were assessed in outdoor stream mesocosms. Imidacloprid pulses reduced invertebrate abundance and community diversity in imidacloprid-dosed streams compared to control streams. These results correlated well with effects of imidacloprid on leaf litter decomposition and feeding rates of Pteronarcys comstocki, a stonefly, in artificial streams. Reductions in oxygen consumption of stoneflies exposed to imidacloprid were also observed in laboratory experiments. Our findings suggest that leaf litter degradation and single species responses can be sensitive ecotoxicological endpoints that can be used as early warning indicators and biomonitoring tools for pesticide contamination. The data generated illustrates the value of mesocosm experiments in environmental assessment and how the consideration of functional and structural endpoints of natural communities together with in situ single species bioassays can improve the evaluation and prediction of pesticide effects on stream ecosystems. Combining organism-level responses with community-level processes for the evaluation and prediction of pesticide effects on stream ecosystems.

This paper compares the dynamics, i.e. the rates of change in element concentrations of young and older lichen thallus parts, of one foliose and one fruticose lichen, during a transplant experiment to a polluted site. Both lichen parts respond to environmental changes. Here, differential accumulation suggests that differential constitution leads to differential uptake and release, and/or the overall behaviour is partly due to internal translocation and regulation mechanisms within the whole lichen. For thallus parts, internal translocation should be taken into account as one more factor affecting lichen “memory length”. Young parts of the thallus presented higher rates of change, but different lichen parts accumulate different elements to different extents. Therefore tissue selection in monitoring may depend on the element of interest, and cannot be made into a generalized approach in survey set-ups: the choice depends on the element. Thallus age and type affect the rate of change of element concentrations in lichens as induced by changes in ambient environmental conditions.

The present study was carried out to understand the current contamination status of organochlorine compounds (OCs) in human breast milk from three metropolitan cities in India (New Delhi, Mumbai and Kolkata). Among the OCs analyzed, DDTs were predominant followed by HCHs and PCBs. CHLs and HCB levels were much lower. Contamination patterns were different in human milk found in our previous study in Chennai, a metropolitan city in southern India, indicating region specific exposure routes and variable sources. In comparison with previous data, levels of DDTs and HCHs generally declined with time, implying the effect of various bans and restrictions on their usage. No association between concentrations of OCs and demographic characteristics such as parity and age of mothers was observed which might be due to narrow range of mother's age. Estimated daily intake shows that some infants are exposed to OCs to a greater extent, particularly HCHs than the guideline standard. Indian infants may be exposed to relatively high levels of DDTs and HCHs through mothers' milk.

This study was carried out in shrimp ponds from New Caledonia, in order to determine the cause of the exceptional proportion of abnormal tests (FAI) (often >50%, sometimes >80%). FAI was positively correlated to the quantity of easily oxidized material (EOM) deposited on the bottom of the ponds and to the sediment oxygen demand, and negatively correlated to redox. These results suggest that a very high FAI is a potential indicator for great accumulations of native organic matter, leading to a high sediment oxygen demand. When studying ancient sediments in core samples, exceptional abundances of abnormal tests may indicate periods of high accumulation of EOM, and therefore of oxygen depletion. This finding should help in better management of aquaculture ponds, but should also allow new insight into the interpretation of sedimentary records, providing a useful proxy for paleoenvironmental reconstructions.

[Departement_IRSTEA]Territoires [TR1_IRSTEA]SYNERGIE | International audience | The strategy of CLIMB is aiming to employ and integrate advan¬ced field monitoring techniques, remote sensing ana-lyses and retrievals, climate models auditing and integra¬ted hydrologic modeling and socioeconomic factor assess¬ment in a new conceptual framework to significantly reduce exist-ing uncertainties in climate change impact analysis. It will create an integrated risk assessment tool for adaptive water resources management and best agricultural practice under climate change conditions. The risk and vulnerability analysis tool will also enable the assess¬ment of risks for conflict-inducing actions. The impro¬ved models, new assessment tools, and their results will be evaluated against current methodologies. Improvements will be communicated to stakeholders and decision makers in a transparent, easy-to-understand form, enabling them to utilize the new findings in regional water resource and agricultural management initiatives as well as in the design of mechanisms to reduce potential for conflict CLIMB is embedded in a cluster of independent EU- projects with WASSERMed and CLICO, focused on climate induced changes in water resources as a threat to security. | L'objectif de la stratégie du projet CLIMB est d'utiliser et d'intégrer des techniques de suivi avancées sur le terrain, des analyses et des recherches de données faisant appel à la télédétection, de vérification de modèles d'évolution climatique et de modélisation par l'intégration hydrologique, et d'évaluation des facteurs socio-économiques dans un cadre conceptuel nouveau afin de réduire de façon significative les incertitudes existantes au sein des analyses des impacts du changement climatique. Ce projet créera un outil intégré d'évaluation du risque qui servira à gérer d'une façon adaptée les ressources en eau et à mettre en ½uvre les meilleures pratiques agricoles possibles dans les conditions du changement climatique. Cet outil d'analyse du risque et de la vulnérabilité permettra aussi l'évaluation des risques dans le cas d'actions conflictuelles. On comparera les modèles améliorés, les nouveaux outils d'évaluation, et leurs résultats aux méthodologies couramment utilisées. On diffusera les progrès obtenus aux parties prenantes et aux décideurs sous une forme transparente et facile à comprendre, leur permettant d'une part d'utiliser les résultats fraichement produits, tant dans les initiatives relatives à la ressource régionale en eau et à la gestion de l'agriculture, et d'autre part de réduire la source de conflit potentiel.

Protecting geotextiles are used in the design of watertight bottom liners at landfill sites, above the géomembrane, to protect it against puncture during the installation of the drainage layer and, during the service life, to the weight of the waste to be put in place. To date, the results of the 2 standard tests (static and dynamic tests) given by the technical sheets for the protecting geotextiles are not sufficient to choose the good geotextile. The development of an experimental procedure to simulate in the lab the waste loading conditions is presented here; this procedure uses large size static damage tests and follows a previous study concerning the implementation dynamic conditions (Budka & al., 2006). | Les géotextiles sont utilisés dans la constitution des étanchéités des installations de stockage de déchets (ISD) pour protéger la géomembrane contre les effets du poinçonnement liés à la mise en oeuvre de la couche de drainage puis, en service, au poids des déchets sus jacents. À ce jour, les deux essais normalisés de poinçonnement, statique et dynamique, figurant sur les fiches techniques des géotextiles de protection ne permettent pas directement le choix du produit adapté. La mise au point d'une procédure d'étude des effets des sollicitations en service est présentée ici ; elle s'appuie sur des essais d'endommagement de grandes dimensions et fait suite à une étude déjà publiée sur l'effet des sollicitations de mise en oeuvre (Budka et al., 2006).

The paper presents parts of the recent guide of recommendations "Mountain reservoirs". It makes a synthesis of a feedback on the behaviour and the pathology of geomembrane lining systems and gives the strong recommendations of the guide relative to these systems, in particular onto the structure support, the drainage inherent to the DEG and the covering structure. A general description of the guide ends the article. | L'article présente, à travers le récent guide de recommandations « Retenues d'altitude », la synthèse d'un retour d'expérience sur le comportement et la pathologie des dispositifs d'étanchéité par géomembrane (DEG) en altitude. Il donne les recommandations fortes du guide relatives à ces dispositifs, en particulier sur la structure support, le drainage inhérent au DEG et la structure de recouvrement. Un descriptif général du guide termine l'article.