DECA: A new model for assessing the foliar uptake of atmospheric lead by vegetation, using Lactuca sativa as an example

In the context of peri-urban atmospheric pollution by industrial lead recycling emissions, metal can transfer to plant shoots. Home gardeners consuming their produce can therefore be exposed to metal pollution. The Human Health Risk Assessment Protocol (HHRAP) model from the United States Environmental Protection Agency (US EPA) classically used in risk assessment provides foliar metal uptake predictions for large farms but is not adapted to cultures in kitchen gardens. Thus, this study developed a new model, entitled “DECA”, which includes individually measured parameters and the washing of vegetables before human consumption. Results given by DECA and HHRAP models were compared with experimental measurements of lettuce. The data calculated by the DECA model were highly correlated with the measured values; the HHRAP model overestimates foliar lead uptake. Moreover, strong influences of factor of washing and time-dependent variations of loss coefficient were highlighted. Finally, the DECA model provided important risk assessment data regarding consumption of vegetables from kitchen gardens

Ecological remediation and sustainable management of an urban industrial site: case of an historical pollution by inorganic potentially toxic elements (Pb, Cd, Cu, Zn, Sb and As)

Rehabilitation of brownfields in urban areas is a major challenge for the sustainable development of cities. Management and conversion of these sites, imposed by regulation, however, require the development of tools for environmental risk assessment and health and sustainable remediation techniques. This thesis focused on the establishment of multidisciplinary tools for the sustainable management of polluted site, with the particular case of rehabilitation recycling of lead batteries with a mainly historical lead pollution and other inorganic pollutants (Cd, Sb, As, Cu and Zn), currently defined as Metal Trace Elements (MTE). While trying to answer questions of applied research, this work has sought to investigate the mechanisms involved in the soil-plant pollutants to strengthen the consideration of the overall quality of soil management for industrial sites. In addition to the tools and procedures conventionally used to assess, control and reduce environmental and health risks caused by polluted soils; measures of bioavailability (plants and humans) and ecotoxicity (different bioassays: inhibition of the mobility of Daphnia magna, Microtox® and induction of bioluminescent bacteria and microbiology) have been developed with the aim to refine the classification of contaminated soils in terms of dangerousness. Moreover, green manure plants (borage, phacelia and mustard), commonly used in agriculture or by gardeners because they improve the bio-physico-chemical properties of soils with a root system and a large production of root exudates were tested for re-functionalization of polluted soils. Finally, the mechanisms involved in the fate of pollutants in the rhizosphere and their microorganisms in the plant were studied. The main results provide some answers and ways of improving the management of soils contaminated by metals and metalloids. (1) First, the size separation for soil fractions allows a significant reduction in tonnages of contaminated material and therefore costs for the landfill excavated soil with a gain result in terms of ecological footprint. (2) Then, calculation for the differents polluted soil samples of eco-scores based on the results of ecotoxicity tests can discriminate more accurately compared to physicochemical parameters required by the regulations. Differences in sensitivity were observed depending on the nature of the bioassay, the origin of the sample, physico-chemical properties and total concentrations of pollutants. (3) Unlike phacelia, borage and mustard improve soil respiration, ecotoxicity and reduce theamount of bioaccessible and total lead in soil, respectively by phytostabilisation and storage in roots (Pb, Sb) or phytoextraction and storage in aerial parts. Further, these plants could be field tested for use in phytoremediation of brownfields and gardens moderately polluted. Depending on the nature of the metal, the type of soil and plant, compartmentalization and speciation of the pollutant differ, and in conjunction with agronomic characteristics of soil and rhizosphere microbial activity. Molecular screening and meta-analysis of microbial genomics have enabled highlight differences in bacterial communities studied by species and growing conditions

Réhabilitation écologique et gestion durable d’un site industriel urbain : cas d’une pollution historique en éléments inorganiques potentiellement toxiques (Pb, Cd, Zn, Cu, Sb et As

La réhabilitation des friches industrielles dans les zones urbaines est un enjeu majeur pour le développement durable des villes. La gestion et la reconversion de ces sites, imposées par la réglementation, nécessitent toutefois le développement d’outils d’évaluation des risques environnementaux et sanitaires, et de techniques de remédiation durables. Cette thèse a porté sur la mise en place d’outils multidisciplinaires pour la gestion durable des sites pollués, avec le cas particulier d’un site de recyclage de batteries au plomb caractérisé par une pollution historique en plomb principalement mais également d’autres polluants inorganiques (Cd, Sb, As, Cu et Zn), couramment définis par le terme d’Eléments Traces Métalliques (ETM). Ce travail a cherché à renseigner les mécanismes impliqués dans les systèmes polluants-sol-plantes pour renforcer la prise en compte de la qualité globale des sols dans la gestion des sites industriels, tout en essayant de répondre à des questions de la recherche appliquée. En plus des outils et procédures classiquement utilisés pour évaluer, contrôler et réduire les risques environnementaux et sanitaires causés par les sols pollués, le développement des mesures de biodisponibilité (plantes et les humains) et d’écotoxicité (différents tests biologiques: inhibition de la mobilité de daphnies, Microtox® et induction de bactéries bioluminescentes, microbiologie) permet d’affiner la classification des sols contaminés en termes de dangerosité. De plus, des plantes engrais verts (bourrache, phacélie et moutarde), communément utilisées en agriculture ou par les jardiniers (car elles améliorent les propriétés bio-physico-chimiques des sols avec un système racinaire et une grande production d’exsudats racinaires), ont été testées pour la re-fonctionnalisation des sols pollués. Enfin, les mécanismes impliqués dans le devenir des polluants dans la rhizosphère et les microorganismes associés ont été étudiés. L’ensemble des résultats fourni des éléments de réponse et des moyens d’améliorer la gestion des sols contaminés par des métaux et métalloïdes. (1) Tout d’abord, la séparation par taille des différentes fractions de sol permet une réduction significative des tonnages de matériaux contaminés et donc une économie réelle lors de la mise en décharge des sols excavés avec un gain certain en termes d’empreinte écologique. (2) Ensuite, le calcul d’écoscores pour les differents échantillons de sols pollués, sur la base des résultats des essais d’écotoxicité, ont permis d’affiner plus précisemment les risques par rapport aux paramètres physico-chimiques « classiques » requis par la réglementation. Des différences de sensibilité ont été observées en fonction de la nature de l’essai biologique, l’origine de l’échantillon, les propriétés physico-chimiques et les concentrations totales de polluants. (3) Contrairement à la phacélie, la bourrache et la moutarde ont amélioré la respiration du sol, réduit l’écotoxicité et la quantité de plomb bioaccessible et totale dans le sol, respectivement par phytostabilisation et stockage dans les racines (Pb, Sb) ou par phytoextraction et donc stockage dans les parties aériennes. En outre, ces plantes pourraient être testées sur le terrain pour une utilisation en phytoremédiation des friches industrielles et des jardins modérément pollués. Selon la nature du métal, du type de sol et des plantes, la compartimentation et la spéciation du polluant diffèrent, ainsi qu’en fonction des caractéristiques agronomiques du sol et l’activité microbienne de la rhizosphère. Un criblage moléculaire et une méta-analyse de la génomique microbienne ont permis de mettre en évidence les différences dans les communautés bactériennes étudiées en fonction du niveau de concentration métallique, des espèces végétales et des caractéristiques des sols étudiés. ABSTRACT : Rehabilitation of brownfields in urban areas is a major challenge for the sustainable development of cities. Management and conversion of these sites, imposed by regulation, however, require the development of tools for environmental risk assessment and health and sustainable remediation techniques. This thesis focused on the establishment of multidisciplinary tools for the sustainable management of polluted site, with the particular case of rehabilitation recycling of lead batteries with a mainly historical lead pollution and other inorganic pollutants (Cd, Sb, As, Cu and Zn), currently defined as Metal Trace Elements (MTE). While trying to answer questions of applied research, this work has sought to investigate the mechanisms involved in the soil-plant pollutants to strengthen the consideration of the overall quality of soil management for industrial sites. In addition to the tools and procedures conventionally used to assess, control and reduce environmental and health risks caused by polluted soils; measures of bioavailability (plants and humans) and ecotoxicity (different bioassays: inhibition of the mobility of Daphnia magna, Microtox® and induction of bioluminescent bacteria and microbiology) have been developed with the aim to refine the classification of contaminated soils in terms of dangerousness. Moreover, green manure plants (borage, phacelia and mustard), commonly used in agriculture or by gardeners because they improve the bio-physico-chemical properties of soils with a root system and a large production of root exudates were tested for re-functionalization of polluted soils. Finally, the mechanisms involved in the fate of pollutants in the rhizosphere and their microorganisms in the plant were studied. The main results provide some answers and ways of improving the management of soils contaminated by metals and metalloids. (1) First, the size separation for soil fractions allows a significant reduction in tonnages of contaminated material and therefore costs for the landfill excavated soil with a gain result in terms of ecological footprint. (2) Then, calculation for the differents polluted soil samples of eco-scores based on the results of ecotoxicity tests can discriminate more accurately compared to physicochemical parameters required by the regulations. Differences in sensitivity were observed depending on the nature of the bioassay, the origin of the sample, physico-chemical properties and total concentrations of pollutants. (3) Unlike phacelia, borage and mustard improve soil respiration, ecotoxicity and reduce theamount of bioaccessible and total lead in soil, respectively by phytostabilisation and storage in roots (Pb, Sb) or phytoextraction and storage in aerial parts. Further, these plants could be field tested for use in phytoremediation of brownfields and gardens moderately polluted. Depending on the nature of the metal, the type of soil and plant, compartmentalization and speciation of the pollutant differ, and in conjunction with agronomic characteristics of soil and rhizosphere microbial activity. Molecular screening and meta-analysis of microbial genomics have enabled highlight differences in bacterial communities studied by species and growing conditions

Metal and metalloid foliar uptake by various plant species exposed to atmospheric industrial fallout: Mechanisms involved for lead

Fine and ultrafine metallic particulatematters (PMs) are emitted frommetallurgic activities in peri-urban zones into the atmosphere and can be deposited in terrestrial ecosystems. The foliar transfer ofmetals andmetalloids and their fate in plant leaves remain unclear, although this way of penetration may be a major contributor to the transfer of metals into plants. This study focused on the foliar uptake of various metals and metalloids from enriched PM(Cu, Zn, Cd, Sn, Sb, As, and especially lead (Pb)) resulting fromthe emissions of a battery-recycling factory.Metal and metalloid foliar uptake by various vegetable species, exhibiting different morphologies, use (food or fodder) and life-cycle (lettuce, parsley and rye-grass) were studied. The mechanisms involved in foliar metal transfer from atmospheric particulate matter fallout, using lead (Pb) as a model element was also investigated. Several complementary techniques (micro-X-ray fluorescence, scanning electron microscopy coupled with energy dispersive X-ray microanalysis and time-of-flight secondary ion mass spectrometry) were used to investigate the localization and the speciation of lead in their edible parts, i.e. leaves. The results showed lead-enriched PM on the surface of plant leaves. Biogeochemical transformations occurred on the leaf surfaces with the formation of lead secondary species (PbCO3 and organic Pb). Some compounds were internalized in their primary form (PbSO4) underneath an organic layer. Internalization through the cuticle or penetration through stomata openings are proposed as two major mechanisms involved in foliar uptake of particulate matter

Influence of fine process particles enriched with metals and metalloids on Lactuca sativa L. leaf fatty acid composition following air and/or soil-plant field exposure

We investigate the effect of both foliar and root uptake of a mixture of metal(loid)s on the fatty acid composition of plant leaves. Our objectives are to determine whether both contamination pathways have a similar effect and whether they interact. Lactuca sativa L. were exposed to fine process particles enriched with metal(loid)s in an industrial area. Data from a first experiment were used to conduct an exploratory statistical analysis which findings were successfully cross-validated by using the data from a second one. Both foliar and root pathways impact plant leaf fatty acid composition and do not interact. Z index (dimensionless quantity), weighted product of fatty acid concentration ratios was built up from the statistical analyses. It provides new insights on the mechanisms involved in metal uptake and phytotoxicity. Plant leaf fatty acid composition is a robust and fruitful approach to detect and understand the effects of metal(loid) contamination on plants

Green manure plants for remediation of soils polluted by metals and metalloids: Ecotoxicity and human bioavailability assessment

Borage, white mustard and phacelia, green manure plants currently used in agriculture to improve soil properties were cultivated for 10 wk on various polluted soils with metal(loid) concentrations representative of urban brownfields or polluted kitchen gardens. Metal(loid) bioavailability and ecotoxicity were measured in relation to soil characteristics before and after treatment. All the plants efficiently grow on the various polluted soils. But borage and mustard only are able to modify the soil characteristics and metal(loid) impact: soil respiration increased while ecotoxicity, bioaccessible lead and total metal(loid) quantities in soils can be decreased respectively by phytostabilization and phytoextraction mechanisms. These two plants could therefore be used for urban polluted soil refunctionalization. However, plant efficiency to improve soil quality strongly depends on soil characteristics

Ecotoxicity tests and ecoscores to improve soil management : case of a secondary lead smelter plant

International audienceriginally located on the outskirts of cities, numerous industrial sites, sometimes abandoned, are now in urban areas and are therefore likely to have environmental and health risks to surrounding populations. Currently, rehabilitation of the sites frequently entails excavation of polluted soils. Excavated soils can thus follow two different ways: landfilling, expensive and energy intensive, or reuse/recycling, integrated to sustainable development. The choice of a specific track mainly depends on total and leachable concentrations of the pollutant in the soil. Among the numerous pollutants observed in urban and peri-urban areas, trace metals are often present in soils; atmosphere emissions by smelters being one of the main anthropogenic source. MTE speciation and compartmentalization in soils can modify their impact on living organisms

Ecotoxicity tests and ecoscores to improve soil management : case of a secondary lead smelter plant

International audienceriginally located on the outskirts of cities, numerous industrial sites, sometimes abandoned, are now in urban areas and are therefore likely to have environmental and health risks to surrounding populations. Currently, rehabilitation of the sites frequently entails excavation of polluted soils. Excavated soils can thus follow two different ways: landfilling, expensive and energy intensive, or reuse/recycling, integrated to sustainable development. The choice of a specific track mainly depends on total and leachable concentrations of the pollutant in the soil. Among the numerous pollutants observed in urban and peri-urban areas, trace metals are often present in soils; atmosphere emissions by smelters being one of the main anthropogenic source. MTE speciation and compartmentalization in soils can modify their impact on living organisms

Use of ecotoxicity test and ecoscores to improve the management of polluted soils: case of a secondary lead smelter plant

International audienceWith the rise of sustainable development, rehabilitation of brownfield sites located in urban areas has become a major concern. Management of contaminated soils in relation with environmental and sanitary risk concerns is therefore a strong aim needing the development of both useful tools for risk assessment and sustainable remediation techniques. For soils polluted by metals and metalloids (MTE), the criteria for landfilling are currently not based on ecotoxicological tests but on total MTE concentrations and leaching tests. In this study, the ecotoxicity of leachates from MTE polluted soils sampled from an industrial site recycling lead-acid batteries were evaluated by using both modified Escherichia coli strains with luminescence modulated by metals and normalized Daphnia magna and Alivibrio fischeri bioassays. The results were clearly related to the type of microorganisms (crustacean, different strains of bacteria) whose sensitivity varied. Ecotoxicity was also different according to sample location on the site, total concentrations and physico-chemical properties of each soil. For comparison, standard leaching tests were also performed. Potentially phytoavailable fraction of MTE in soils and physico-chemical measures were finally performed in order to highlight the mechanisms. The results demonstrated that the use of a panel of microorganisms is suitable for hazard classification of polluted soils. In addition, calculated eco-scores permit to rank the polluted soils according to their potentially of dangerousness. Influence of soil and MTE characteristics on MTE mobility and ecotoxicity was also highlighted