263 research outputs found
A bacterium-based contact assay for evaluating the quality of solid samples - Results from an international ring-test
No full textAbstract not availableCatarina R. Marques, Najoi El-Azhari, Fabrice Martin-Laurent, Pascal Pandard, Camille Meline, Alice L. Petre, Suzanne Eckert, Jürgen Zipperle, Martin Váňa, Stanislav Maly, Lucie Šindelářová, Anna Slavíková, Amemorih, Jakub Hofman, Anu Kumari, Hai Doan, Mike McLaughlin, Elizabeth Richter, Jörg Römbk
Establishing validated concentration limits for ecotoxicological tests HP 14 for waste
No full textInternational audienceThe hazard properties of waste in Europe are defined in the Commission Regulation (EU) N° 1357/2014 of 18 December 2014 replacing Annex III to Directive 2008/98/EC of the European Parliament and of the Council on waste and repealing certain Directives, excepted for the most frequent one, HP 14 ‘Ecotoxic’ (Hennebert et al. 2014). The Directorate General Environment launched in May, 2014 a “Call for tenders ENV.A.2/ETU/2014/0023r - Study to assess the impacts of different classification approaches for hazard property “H 14” on selected waste streams”, HP 14 being calculated from the chemical composition of the waste with different methods. The results of this study are not published at the time of this abstract. An independent study on 120 wastes has ranked the four calculation methods that are proposed (Hennebert et al. 2016) and has tested a 5th variant with multiplying factors for the most ecotoxic substances (M-factors of the CLP), with 80% matching with the European List of Waste. For these calculation methods, the speciation of the elements into substances must be hypothesized. Ecotoxicological tests could provide a straightforward classification without hypothesis of speciation. It is accepted in chemical regulation that results of tests overwhelm results of calculations. The design of the toxicity tests follows a dose/response or dilution approach, meaning that the waste (eluate or solid) is mixed with different amount of a control substrate (e.g. culture medium of reconstituted water or artificial soil), and that a biological parameter is measured for each dilution. The results of these tests can be expressed as ECx values (concentration of eluate or solid in the mixture with the control substrate producing a biological effect of x %, namely 20% or 50% of growth, mobility, reproduction, etc.). An EC50 of 8% means that a dilution of the culture media with 8% of waste produces a reduction of 50% of i.e. mobility. Preparation of eluates (liquid/solid ratio = 10 l/kg dry matter, 24h) and mixtures of waste with control substrate are carried out according to EN 14735. An aquatic and terrestrial tests battery with bacteria, plant and invertebrate animal is proposed by Pandard and Römbke (2013), from a previous proposal of Ökopoll (2008). The test battery can be operated stepwise, and stopped if one test result is lower than its proposed concentration limits. In France a previous proposal of 1997 is used, sometimes in a modified version in 2006 (Pandard et al 2006). Concentration limits of 10% for acute tests and 1% for chronic tests are proposed but without validation, and unsatisfactory results. If one of the ECx values measured by the tests for a given waste is below its concentration limit, the waste is classified as hazardous. The waste is considered as non-hazardous only if the results of all ECx values are above their respective concentration limits. Hence, a validated concentration limit (classifying the waste hazardous or non hazardous) for each test should be the lowest ECx value measured with a panel of non ecotoxic waste (by the European List of Waste taken as reference). Simultaneously, it must be checked with a panel of ecotoxic waste that at least one ECx is below the proposed concentration limits. The results of this original method will be presented in the paper
Daphnia tests
No full textThe proposed test strategy combined the direct and indirect approaches, integrating organisms representing the terrestrial and aquatic ecosystems. For the latter, several tests were selected; the Daphnia magna mobility test, the algal growth inhibition test and the inhibition of light emission of Vibrio fischeri were considered as a basic test set. From a methodological point of view, no significant problems were reported during the ring test. A total of 149 tests out of the 161 tests conducted were considered acceptable. The overall results showed that the D. magna mobility test was highly sensitive to incineration ash and contaminated wood eluates. On the other hand, high variability in the results was observed mainly for the contaminated wood eluate (INC, min-max: 10; WOO, min-max: 31). The CVs were 62 and 103% for INC and WOO respectively. In contrast to the terrestrial tests, the variability of the results shows not only the variability of the ecotoxicity test itself, but also integrates the variability of the overall procedure: sampling of the test portion, eluate preparation (leaching procedure, separation of the solid and liquid phases) and the ecotoxicity test. It may partly explain the high variability of the results of the waste tests compared with those observed for tests with the reference chemical
Interest of soil microfauna organisms to determine the ecotoxicity of fertilizing matters and wastes used in agriculture : the nematode Caenorhabditis elegans and the predatory mite Hypoaspis aculeifer
No full textLes résultats obtenus au cours des travaux de thèse traitent dans une première partie de l’applicabilité et des limitations des bio-essais à l’étude des MF (problématiques telles que l’hydratation des échantillons, l’apport de nourriture, l’extraction des organismes de matrices complexes,…). D’autre part, la réponse des critères d’effet étudiés pour chacun des deux organismes (i.e. mortalité, croissance, et reproduction pour C. elegans ainsi que mortalité et reproduction pour H. aculeifer) a été renseignée après exposition à différentes substances chimiques préconisées en tant que substances de référence. La deuxième partie présente la sensibilité des organismes étudiés par rapport à des éléments contaminant (i.e. ETM) pouvant potentiellement être apportés au sol lors de l’épandage de MF. La dernière partie des résultats concerne l’évaluation de différentes MF par approche directe et indirecte, en utilisant les critères d’effet définis pour les deux organismes modèles. La discussion des travaux de thèse est axée en premier lieu sur la comparaison de la sensibilité des critères d’effet suivis chez les deux organismes modèles pour les différentes substances chimiques étudiées. Dans un second temps, la pertinence d’intégrer les organismes modèles C. elegans et H. aculeifer dans des batteries de bio-essais est discutée, cela afin de proposer, à terme, une stratégie expérimentale permettant une caractérisation a priori des dangers pour l’environnement liés à l’utilisation agricole des MFFertilizing matters (FM) can be hazardous to the environment during application, due to the potential presence of contaminants. The approval process involves demonstrating the safety of these matrices towards the environment, but there is no ecotoxicological test strategy to date. In this context, tests using the nematode C. elegans and the predatory mite H. aculeifer have been proposed in a battery of bioassays, as new model organisms for the ecotoxicological assessment of FM. The results obtained with C. elegans and H. aculeifer by direct and indirect approaches were compared and discussed in relation to those obtained for other terrestrial (plants and earthworms) and aquatic organisms (bacteria, algae, rotifers and crustaceans) in order to provide, in fine, a relevant test strategy to assess the environmental hazards of the agricultural use of F
Etude de biocapteurs, a algues immobilisees pour le controle des milieux hydriques
No full textSIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 81418 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Utilisation d’une approche multicritère pour la sélection d’essais d’écotoxicité
No full textInternational audienceSensitivity of animal and plant communities to toxicants may vary significantly from one species to another. If testing is performed on one species, the high diversity in the sensitivity between species might result in a high level of uncertainty. It is therefore admitted that only a combination of several bioassays can give a clear view of the toxic effects of chemicals and/or environmental samples. The best approach is therefore to use a battery of tests with several species belonging to different taxonomic groups and trophic levels. Usually, two methods can be used for selecting bioassays in order to establish a test battery: i) an “a priori” method, in which the selection is made according to decision criteria such as standardization of the method, ecological relevance of test organisms, or cost, ii) an “a posteriori” method, in which the selection is made after performing multivariate analyses of test results obtained on a large series of bioassays. In the present study on soil quality, a methodological framework, based on the use of the multicriteria method SIRIS (System of Integration of Risk with Interaction of Scores) was applied to perform an “a priori ” selection of bioassays among 115 relevant ecotoxicity tests, selected from an extensive literature review.L’utilisation d’essais sur organismes biologiques est désormais reconnue comme l’un des éléments pertinents permettant de caractériser de façon satisfaisante la qualité des milieux. En effet, ces outils prennent en compte, à la fois la biodisponibilité - disponibilité pour les organismes vivants - des différentes substances chimiques présentes, mais également les effets de synergie ou d’antagonisme qui peuvent se produire entre ces dernières. Ces essais biologiques, initialement utilisés pour le contrôle des substances chimiques et des rejets en milieu aquatique, sont aujourd’hui appliqués à d’autres domaines tels que la caractérisation des sites et des sols pollués, la valorisation des boues en agriculture, la gestion des sédiments ainsi que la classifi cation des déchets
Daphnia tests
No full textThe proposed test strategy combined the direct and indirect approaches, integrating organisms representing the terrestrial and aquatic ecosystems. For the latter, several tests were selected; the Daphnia magna mobility test, the algal growth inhibition test and the inhibition of light emission of Vibrio fischeri were considered as a basic test set. From a methodological point of view, no significant problems were reported during the ring test. A total of 149 tests out of the 161 tests conducted were considered acceptable. The overall results showed that the D. magna mobility test was highly sensitive to incineration ash and contaminated wood eluates. On the other hand, high variability in the results was observed mainly for the contaminated wood eluate (INC, min-max: 10; WOO, min-max: 31). The CVs were 62 and 103% for INC and WOO respectively. In contrast to the terrestrial tests, the variability of the results shows not only the variability of the ecotoxicity test itself, but also integrates the variability of the overall procedure: sampling of the test portion, eluate preparation (leaching procedure, separation of the solid and liquid phases) and the ecotoxicity test. It may partly explain the high variability of the results of the waste tests compared with those observed for tests with the reference chemical
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