International audience | This study examined the long-term effects of the landfill disposal of untreated urban waste for soil fertilization on the prevalence and antibiotic resistance profiles of various human opportunistic pathogens in soils from Burkina Faso. Samples were collected at three sites in the periphery of Ouagadougou during two campaigns in 2008 and 2011. At each site, amendment led to changes in physico-chemical characteristics as shown by the increase in pH, CEC, total C, total N, and metal contents. Similarly, the numbers of total heterotrophic bacteria were higher in the amended fields than in the control ones. No sanitation indicators, i.e., coliforms, Staphylococci, and Enterococci, were detected. Pseudomonas aeruginosa and Burkholderia cepacia complex (Bcc) were d e t e c t e d a t a l o w l e v e l i n o n e a m e n d e d f i e l d. Stenotrophomonas maltophilia was detected from both campaigns at the three sites in the amended fields and only once in an unamended field. Diversity analysis showed some oppor-tunistic pathogen isolates to be closely related to reference clinical strains responsible for nosocomial-or community-acquired infections in Northern countries. Antibiotic resistance tests showed that P. aeruginosa and Bcc isolates had a wild-type phenotype and that most S. maltophilia isolates had a multi-drug resistance profile with resistance to 7 to 15 antibiotics. Then we were able to show that amendment led to an increase of some human opportunistic pathogens including multi-drug resistant isolates. Although the application of untreated urban waste increases both soil organic matter content and therefore soil fertility, the consequences of this practice on human health should be considered.

International audience | A conceptual model was constructed for the functioning the algae-dominated rocky reef ecosystem of the Med-iterranean Sea. The Ecosystem-Based Quality Index (reef-EBQI) is based upon this model. This index meets the objectives of the EU Marine Strategy Framework Directive. It is based upon (i) the weighting of each compartment , according to its importance in the functioning of the ecosystem; (ii) biological parameters assessing the state of each compartment; (iii) the aggregation of these parameters, assessing the quality of the ecosystem functioning , for each site; (iv) and a Confidence Index measuring the reliability of the index, for each site. The reef-EBQI was used at 40 sites in the northwestern Mediterranean. It constitutes an efficient tool, because it is based upon a wide set of functional compartments, rather than upon just a few species; it is easy and inexpensive to implement, robust and not redundant with regard to already existing indices.

International audience

Of the wide variety of dumped objects containing radioactive materials in the Arctic seas, the submarine K-27 constitutes a major risk due to the large amount of highly enriched uranium onboard and its location in shallow waters. As the matter of potential operations involving raising of the submarine have entered the public arena, a priori assessment of the contamination in the Arctic marine environment that could result after a possible accident during such operations is a matter of some interest. The dispersion of contaminants within the Arctic has been assessed using a large scale hydrodynamic model for a series of plausible accident scenarios and locations under different oceanographic regimes. Results indicate that, depending primarily on the nature of a release (i.e. instantaneous or continuous), large areas of the Arctic marine environment will exhibit contamination to varying degrees.

International audience

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]INSPIRE | International audience | In typical life cycle impact assessment (LCIA) studies of urban wastewater systems (UWS), average conditions are modelled but there are many annual flooding events with releases of raw sewage. Such peak conditions are not considered and present a high temporal variability which is not currently accounted for. In addition, the aggregation of the loads from several storm events could bring an issue for the impact assessment on the aquatic categories of eutrophication and ecotoxicity. Hence we are investigating the contributions of these wet weather-induced discharges along with the inclusion of temporal variability in the life cycle inventory (LCI) for UWS.

Contamination of aquatic ecosystems is considered as one of the main threats to global freshwater biodiversity. Within the European Water Framework Directive (EU-WFD) a particular attention is dedicated to assess ecological risks of surface water contamination and mitigation of chemical pressures on aquatic ecosystems. In this work, we evaluated ecological risks of surface water contamination for fish populations in four EU-WFD rivers through an integrative approach investigating three Lines of Evidence (chemical contamination, biomarker responses as early warning signals of contamination impacting individuals and ecological analyses as an indicator of fish community disturbances). This work illustrates through 4 case studies the complementary role of biomarkers, chemical and ecological analyses which, used in combination, provide fundamental information to understand impacts of chemical pressures that can affect fish population dynamics. We discuss the limitations of this approach and future improvements needed within the EU-WFD to assess ecological risk of river contamination for fish populations.

Ozone (O3) is a photochemically formed reactive gas responsible for a decreasing carbon assimilation in plant ecosystems. Present in the atmosphere in trace concentrations (less than 100 ppbv), this molecule is capable of inhibiting carbon assimilation in agricultural and forest ecosystems. Ozone-risk assessments are typically based on manipulative experiments. Present regulations regarding critical ozone levels are mostly based on an estimated accumulated exposure over a given threshold concentration. There is however a scientific consensus over flux estimates being more accurate, because they include plant physiology analyses and different environmental parameters that control the uptake—that is, not just the exposure—of O3. While O3 is a lot more difficult to measure than other non-reactive greenhouse gases, UV-based and chemiluminescence sensors enable precise and fast measurements and are therefore highly desirable for eddy covariance studies. Using micrometeorological techniques in association with latent heat flux measurements in the field allows for the partition of ozone fluxes into the stomatal and non-stomatal sinks along the soil-plant continuum. Long-term eddy covariance measurements represent a key opportunity in estimating carbon assimilation at high-temporal resolutions, in an effort to study the effect of climate change on photosynthetic mechanisms. Our aim in this work is to describe potential of O3 flux measurement at the canopy level for ozone-risk assessment in established long-term monitoring networks.

International Symposium on Effect-Related Evaluation of Anthropogenic Trace Substances - Concepts for Genotoxicity Neurotoxicity and Endocrine Effects, Aachen, october 2015 | Understanding the fate and ecotoxicological effects of pesticides largely depends on their molecular properties. We recentlydeveloped BTyPol^ (Typology of Pollutants), a classification method of organic compounds based on statistical analyses. Itcombines several environmental (sorption coefficient, degradation half-life) and one ecotoxicological (bioconcentration factor)parameters, to structural molecular descriptors (number of atoms in the molecule, molecular surface, dipole moment, energy oforbitals, etc.). The present study attempts to extend TyPol to the ecotoxicological effects of pesticides on non-target organisms,based on data analysis from available literature and databases. It revealed that relevant ecotoxicological endpoints for terrestrialorganisms (e.g., soil microorganisms, invertebrates) that support a range of ecosystemic services are lacking as compared toaquatic organisms. The availability of ecotoxicological parameters was also lower for chronic than for acute ecotoxicity endpoints.Consequently, seven parameters were included for acute (EC50, LC50) and chronic (NOEC) ecotoxicological effects forone terrestrial (Eisenia sp.) and three aquatic (Daphnia sp., algae, Lemna sp.) organisms. In this new configuration, we usedTyPol to classify 50 pesticides into different clusters that gather molecules with similar environmental behaviors and ecotoxicologicaleffects. The classification results evidenced relationships between molecular descriptors, environmental parameters, andthe added ecotoxicological endpoints. This proof-of-concept study also showed that TyPol in silico classification can successfullyaddress new scientific questions and be expanded with other parameters of interest.

The concentrations of 17 non-essential elements (Al, As, Ba, Be, Cd, Ce, Cr, Hg, La, Li, Pb, Sb, Sn, Sr, Th, Ti, and Tl) were determined in brown grain rice samples of two varieties: Fortuna and Largo Fino. The samples were collected from the four main producing regions of Corrientes province (Argentina). Quantitative determinations were performed by inductively coupled plasma mass spectrometry (ICP-MS), using a validated method. The contents of As, Be, Cd, Ce, Cr, Hg, Pb, Sb, Sn, Th, and Tl were very low or not detected in most samples. The non-essential element levels detected were in line with studies conducted in rice from different parts of the world. In order to characterize the influence of geographical origin in the samples, the following classification methods were carried out: linear discriminant analysis (LDA), k-nearest neighbors (k-NN), partial least squares discriminant analysis (PLS-DA), support vector machine (SVM) and random forests (RF). The best performance was obtained by using RF (96%) and SVM (96%). The results reported here showed the variation in the non-essential element profiles in rice grain depending on the geographical origin.