Background, aim, and scope Selenium is a trace metalloid of global environmental concern. The boundary among its essentiality, deficiency, and toxicity is narrow and mainly depends on the chemical forms and concentrations in which this element occurs. Different plant species--including Brassica juncea--have been shown to play a significant role in Se removal from soil as well as water bodies. Furthermore, the interactions between such plants, showing natural capabilities of metal uptake and their rhizospheric microbial communities, might be exploited to increase both Se scavenging and vegetable biomass production in order to improve the whole phytoextraction efficiency. The aim of the present study was to evaluate the capability of selenite removal of B. juncea grown in hydroponic conditions on artificially spiked effluents. To optimize phytoextraction efficiency, interactions between B. juncea and rhizobacteria were designedly elicited. Materials and methods Firstly, B. juncea was grown on water-filtering agriperlite beds in the presence of three different selenite concentrations, namely, 0.2, 1.0, and 2.0 mM. Plant growth was measured after 3 and 6 weeks of incubation in order to establish the selenite concentration at which the best plant biomass production could be obtained. Afterwards, water-filtering agriperlite beds were inoculated either with a selenium-acclimated microbial community deriving from the rhizosphere of B. juncea grown, erstwhile, in a selenite-amended soil or with axenic cultures of two bacterial strains, vicelike Bacillus mycoides SeITE01 and Stenotrophomonas maltophilia SeITE02, previously isolated and described for their high resistance to selenite. These latter were seeded separately or as a dual consortium. Selenite was amended at a final concentration of 1.0 mM. Total Se content in plant tissues (both shoots and roots), plant biomass production, and persistence of bioaugmented microbial inocula during the experimental time were monitored. Moreover, parameters such as bioconcentration factor (BF) and phytoextraction efficiency (PE) were determined at the end of the testing run to evaluate the effects of the different bioaugmentation strategies adopted on selenite phytoextraction efficiency of B. juncea. Results A general but significant increase in capacity to extract and transport selenium to the epigeous plant compartments was recorded in B. juncea grown in beds augmented with microbial inocula, except for the treatment with B. mycoides SeITE01 alone. Nevertheless, a severe decrease in vegetable biomass production was observed after all microbial treatments with the exception of the plants that had received only S. maltophilia SeITE02. Actually, an increase in selenium phytoextraction efficiency up to 65% was observed in B. juncea, when this bacterial strain was inoculated. Discussion Emendation of B. juncea grown in water-filtering beds with a Se(IV)-acclimated microbial community caused a higher Se uptake along with a reduction of plant biomass yield with respect to plants grown without addition of the same bacterial inoculum. The increase of selenium BF in shoots suggests that the Se(IV)-acclimated microbial community not only elicited the plant capacity to absorb selenite, but also did improve the capacity to transport the metalloid to the epigeous compartments. On the other hand, the reduction in plant biomass yield might be related exactly to this improved capability of B. juncea to accumulate selenium at concentrations that are actually toxic for plants. Differently, addition of two selenite-resistant bacterial strains, namely, S. maltophilia SeITE02 and B. mycoides SEITE01, had weaker effects on plant biomass production when compared to those recorded in the presence of the Se(IV)-adapted microbial community. In particular, inoculation of water-filtering beds with the SeITE02 strain alone was the sole strategy resulting in a positive effect on both plant biomass production in stressful conditions and the capacity of shoots to accumulate selenium. In fact, its putative ability of reducing Se(IV) to organo-Se compounds significantly enhanced either selenium absorption by the plants or active metalloid translocation to epigeous parts. Conclusions Bioaugmentation with the bacterial strain S. malthophila SeITE02 is suggested to elicit selenite phytoextraction efficiency in B. juncea. Recommendations Manipulation of synergistic interactions between plants having phytoextraction capabilities and their associated rhizobacteria may enhance already consolidated treatment processes aimed to detoxify selenite laden wastewater.

Chlordecone was applied between 1972 and 1993 in banana fields of the French West Indies. This resulted in long-term pollution of soils and contamination of waters, aquatic biota, and crops. To assess pollution level and duration according to soil type, WISORCH, a leaching model based on first-order desorption kinetics, was developed and run. Its input parameters are soil organic carbon content (SOC) and SOC/water partitioning coefficient (Koc). It accounts for current chlordecone soil contents and drainage water concentrations. The model was valid for andosol, which indicates that neither physicochemical nor microbial degradation occurred. Dilution by previous deep tillages makes soil scrapping unrealistic.Lixiviation appeared the main way to reduce pollution. Besides the SOC and rainfall increases, Koc increased from nitisol to ferralsol and then andosol while lixiviation efficiency decreased. Consequently, pollution is bound to last for several decades for nitisol, centuries for ferralsol, and half a millennium for andosol.

Production of methane and carbon dioxide as well as methane concentrations in surface waters and emissions to the atmosphere were investigated in two flow-through lake complexes (Uzlina-Isac and Puiu-Rosu-Rosulet) in the Danube Delta during post-flood conditions in May and low water level in September 2006. Retained nutrients fuelled primary production and remineralisation of bioavailable organic matter. This led to an observable net release of methane, particularly in the lakes Uzlina, Puiu and Rosu in May. Input from the Danube River, from redbuds and benthic release contributed to CH₄ concentrations in surface waters. In addition to significant river input of CO₂, this trace gas was released via aerobic remineralisation within the water column and in top sediments. Emission patterns of CO₂ widely overlapped with those of CH₄. Generally, greenhouse gas emissions peaked in the lake complex adjacent to the Danube River in May due to strong winds and decreased with increasing hydrological distance from the Danube River. Intense remineralisation of organic matter in the Danube Delta lakes results in a net source of atmospheric greenhouse gases.

Background, aim, and scope Dicofol is widely used as a pesticide in agriculture applications. Since dicofol is mainly synthesized from dichlorodiphenyltrichlorethane (DDT), it contains DDT as an impurity. The European Community has forced Prohibition Directive 79/117/EEC to reduce DDT in dicofol formulations. Specifically, DDT content in a dicofol formulation cannot exceed 0.1%. The goal of this project was to determine the DDT content in dicofol formulations used in Turkey. Materials and methods Samples of all the dicofol formulations in Turkey were collected to quantify DDT and DDT-related compounds. Four replicates were used for each sample. GC/MS/MS was used to analyze p,p' and o,p' isomers of DDT, DDD, and DDE. A HPLC was used to determine p,p'-Cl-DDT concentrations. Results The total DDT content of the formulated dicofol was found between 0.3% and 14.3%. The concentration of p,p'-DDE ranged from 167 to 1,042 mg kg⁻¹ in dicofol samples. p,p'-DDT concentrations were found to be 32 to 183 mg kg⁻¹. The o,p'-DDT level ranged from 2 to 34 mg kg⁻¹ in the dicofol formulations analyzed. Discussion It was estimated that 617.8 kg of DDT was released from dicofol. The main impurity was identified as p,p-Cl-DDT. Based on these results, dicofol serves as a continuing source of DDT contamination. Conclusions All DDT concentrations in dicofol samples analyzed were higher than the permitted 0.1% level of Prohibition Directive 79/117/EEC. The reduction of dicofol is critical since it serves as a continual source of DDT contamination. Recommendations and perspectives DDT has been found in soil, water, and air samples. Dicofol has been identified as a contributor to continued DDT contamination in soil and water. More studies are needed to ascertain the source of DDT in the air.

Background, aim, and scope Food consumption is an important route of human exposure to endocrine-disrupting chemicals. So far, this has been demonstrated by exposure modeling or analytical identification of single substances in foodstuff (e.g., phthalates) and human body fluids (e.g., urine and blood). Since the research in this field is focused on few chemicals (and thus missing mixture effects), the overall contamination of edibles with xenohormones is largely unknown. The aim of this study was to assess the integrated estrogenic burden of bottled mineral water as model foodstuff and to characterize the potential sources of the estrogenic contamination. Materials, methods, and results In the present study, we analyzed commercially available mineral water in an in vitro system with the human estrogen receptor alpha and detected estrogenic contamination in 60% of all samples with a maximum activity equivalent to 75.2 ng/l of the natural sex hormone 17β-estradiol. Furthermore, breeding of the molluskan model Potamopyrgus antipodarum in water bottles made of glass and plastic [polyethylene terephthalate (PET)] resulted in an increased reproductive output of snails cultured in PET bottles. This provides first evidence that substances leaching from plastic food packaging materials act as functional estrogens in vivo. Discussion and conclusions Our results demonstrate a widespread contamination of mineral water with xenoestrogens that partly originates from compounds leaching from the plastic packaging material. These substances possess potent estrogenic activity in vivo in a molluskan sentinel. Overall, the results indicate that a broader range of foodstuff may be contaminated with endocrine disruptors when packed in plastics.

Background, aim, and scope Bombing and destruction of the industrial and military targets accompanied by complete or incomplete combustion during the war conflict and NATO operation in former Yugoslavia caused the emission of persistent organic pollutants into the atmosphere, water, and soil. A total of 129 ambient air samples from 24 background, urban, and industrial sites, including hot spots, were collected to assess a gas-particle partitioning behavior of various persistent organic pollutants. Materials and methods High volume sampling technique was applied with quartz filters that collect the atmospheric particles and polyurethane foam filters (PUF) that retain the gaseous compounds. Three to ten samples were taken at each site. GFs and PUFs were analyzed separately for their content of polychlorinated biphenyls, organochlorine pesticides, and polyaromatic hydrocarbons. Results Gas phase and particle phase concentrations of selected persistent organic pollutants (POPs) in all samples were converted into the particle-bound fractions [Greek Phi symbol]. These fractions were found to be highly variable, but generally highest in Bosnia and Herzegovina due to the elevated levels of total suspended material in ambient air. Discussion Experimental values of particle-associated fraction were compared to the Junge-Pankow model. Interestingly, a model for urban/industrial environments provided a better prediction of partitioning behavior than a model for background and rural background sites. That is probably because the total amount of atmospheric particles is higher in the Balkan region than found in the previously published studies. Conclusions Even though it has been stated in previous studies that less than 5% of polychlorinated biphenyls (PCBs) are bound to the particles, up to 67% of PCBs were particle associated at several sampling sites in this study. PCB-contaminated soils are probably still one of the strong sources of particles to the atmosphere. Recommendations and perspectives Information on the particle-bound fractions of POPs is important not only for prediction of their fate but also for an estimation of risks they can pose to the environment as well as to humans. When assessing such hazards, it has to be considered that modeled values of the particle-bound fractions can be seriously underestimated at sites with elevated levels of suspended atmospheric matter or at sites with heavily contaminated soils.

Background, aim and scope Agricultural landscapes comprise cultivated fields and semi-natural areas. Biological components of these compartments such as weeds, insect pests and pathogenic fungi can disperse sometimes over very large distances, colonise new habitats via insect flight, spores, pollen or seeds and are responsible for losses in crop yield (e.g. weeds, pathogens) and biodiversity (e.g. invasive weeds). The spatiotemporal dynamics of these biological components interact with crop locations, successions and management as well as the location and management of semi-natural areas such as roadverges. The objective of this investigation was to establish a modelling and simulation methodology for describing, analysing and predicting spatiotemporal dynamics and genetics of biological components of agricultural landscapes. The ultimate aim of the models was to evaluate and propose innovative cropping systems adapted to particular agricultural concerns. The method was applied to oilseed rape (OSR) volunteers playing a key role for the coexistence of genetically modified (GM) and non-GM oilseed rape crops, where the adventitious presence of GM seeds in non-GM harvests (AGMP) could result in financial losses for farmers and cooperatives. Material and methods A multi-year, spatially explicit model was built, using field patterns, climate, cropping systems and OSR varieties as input variables, focusing on processes and cultivation techniques crucial for plant densities and pollen flow. The sensitivity of the model to input variables was analysed to identify the major cropping factors. These should be modified first when searching for solutions limiting gene flow. The sensitivity to model processes and species life-traits were analysed to facilitate the future adaptation of the model to other species. The model was evaluated by comparing its simulations to independent field observations to determine its domain of validity and prediction error. Results The cropping system study determined contrasted farm types, simulated the current situation and tested a large range of modifications compatible with each farm to identify solutions for reducing the AGMP. The landscape study simulated gene flow in a large number of actual and virtual field patterns, four combinations of regional OSR and GM proportions and three contrasted cropping systems. The analysis of the AGMP rate at the landscape level determined a maximum acceptable GM OSR area for the different cropping systems, depending on the regional OSR volunteer infestation. The analysis at the field level determined minimum distances between GM and non-GM crops, again for different cropping systems and volunteer infestations. Discussion The main challenge in building spatially explicit models of the effects of cropping systems and landscape patterns on species dynamics and gene flow is to determine the spatial extent, the time scale, the major processes and the degree of mechanistic description to include in the model, depending on the species characteristics and the model objective. Conclusions These models can be used to study the effects of cropping systems and landscape patterns over a large range of situations. The interactions between the two aspects make it impossible to extrapolate conclusions from individual studies to other cases. The advantage of the present method was to produce conclusions for several contrasted farm types and to establish recommendations valid for a large range of situations by testing numerous landscapes with contrasted cropping systems. Depending on the level of investigation (region or field), these recommendations concern different decision-makers, either farmers and technical advisors or cooperatives and public decision-makers. Recommendations and perspectives The present simulation study showed that gene flow between coexisting GM and non-GM varieties is inevitable. The management of OSR volunteers is crucial for containing gene flow, and the cropping system study identified solutions for reducing these volunteers and ferals in and outside fields. Only if these are controlled can additional measures such as isolation distances between GM and non-GM crops or limiting the proportion of the region grown with GM OSR be efficient. In addition, particular OSR varieties contribute to limit gene flow. The technical, organisational and financial feasibility of the proposed measures remains to be evaluated by a multi-disciplinary team.

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [Axe_IRSTEA]TED-SOWASTE | National audience | This papers aims at presenting the various lining and drainage structures including geosynthetics that can be encountered in mining applications like heap leach pads, tailing storage facilities and waste rock storage facilities. The question of design and durability of drainage and lining systems is then discussed as regards the impact of the large loads that can be encountered in mining applications. Then liquid and gas transfers are discussed together with the attenuation of metals in GCLs. | Cet article permet, après une présentation de différentes structures à base de géosynthétiques rencontrées dans les installations minières ,aires de lixiviation, zones de stockage de résidus de lixiviation,ainsi que stockages de stériles, de discuter des structures d'étanchéité et de drainage mises en place dans ces structures. On aborde ensuite la problématique du dimensionnement et de la durabilité des systèmes drainants et d'étanchéité sous les fortes contraintes mécaniques typiquement rencontrées dans les installations minières. Puis on discute les transferts liquides et gazeux ainsi que l'atténuation des métaux dans les géosynthétiques bentonitiques.

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [Axe_IRSTEA]TED-SOWASTE | National audience | The objective of the Equivalence Guide is to define rules of good practice with respect to equivalent solutions for landfill mineral barriers. The guide refers primarily to non-hazardous waste landfills. The guide, which was first drafted in 2002, was updated in 2008, by a working group composed of the main organisations working on landfill mineral barriers in France. The update also benefited from feedback from professional partners (consultants, landfill operators, geosynthetic suppliers...). This paper summarizes the main changes with respect to the previous version. | Le « Guide Équivalence » a pour objectif de définir des règles de bonne pratique en matière de recherche de solutions « équivalentes » en étanchéité passive d'installation de stockage de déchets. Les principaux sites concernés par ce guide sont les installations de stockage de déchets non dangereux (ISDND). Ce guide, dont la première version date de 2002, a été réactualisé par un groupe de travail constitué des principaux organismes intervenant sur la thématique des barrières minérales d'ISD en France. Cette réactualisation a également bénéficié d'un retour d'expérience recueilli auprès de la profession (bureaux d'étude, exploitants, fournisseurs de géosynthétiques ). Cet article fait une synthèse des principales modifications par rapport à la version antérieure.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE | National audience | 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.