Evaluation du devenir des produits phytopharmaceutiques en plein champ en fonction des pratiques culturales pour le développement d’une agriculture éco responsable (Sol-Phy-Ly). Rapport d’activités final 2018-2021.

Sol-Phy-L

Evaluation du devenir des produits phytopharmaceutiques en plein champ en fonction des pratiques culturales : Sol-Phy-Ly

Sol-Phy-L

Identification of volatiles organics compounds indoor sources and their contributions at observed concentrations in French dwellings

Les atmosphères intérieures se révèlent très riches en composés organiques volatils (COV). Ces substances forment un « cocktail à risque » dont la composition et les effets sur la santé restent encore méconnu. Cette complexité rend difficile l’identification et la quantification des sources intérieures sur la qualité de l’air. Cette thèse a pour but d’établir des relations qualitatives et quantitatives entre les sources intérieures de COV et les teneurs observées dans des logements français. Le premier axe de travail porte sur le développement de la mesure passive pour déterminer les taux d’émission en formaldéhyde (FA) et en acétaldéhyde des matériaux. Ce préleveur a été validé en laboratoire, puis utilisé in-situ, dans une campagne de mesures réalisée dans des chambres étudiantes. Ce diagnostic sur site montre que le mobilier et les matériaux du bâti de la pièce contribuent à part égale à la concentration intérieure en FA. L’augmentation des émissions est clairement influencée par l’élévation de la température. Un modèle d’équilibre des masses basé sur les taux d’émission mesurés a conduit à une prédiction satisfaisante des concentrations en FA dans les 24 lieux échantillonnés. Le second axe porte sur l’analyse des profils chimiques de 60 logements. A partir d’un « screening » des COV ; des classes homogènes de profils chimiques associés aux logements ont pu être établies. Des hypothèses sur les sources potentielles de ces composés ont été formulées et examinées sur la base des données de la littérature, des questionnaires descriptifs des logements et des émissions de matériaux et produits présents en environnement intérieur.Indoor atmospheres appear very rich in volatile organic compounds (VOC). These substances form a “dangerous mix” whose composition and effects on health remain still unknown. This complexity makes difficult the identification and the quantification of indoor sources on the indoor air quality. The purpose of this thesis is to establish qualitative and quantitative relationship between VOC indoor sources and the concentrations observed in French dwellings. The first axis of this work deals with the development of passive measurement to determine the formaldehyde (FA) and acetaldehyde emission rates of materials. This sampler was validated in laboratory, then used in-situ, in a batch of measurements carried out in student rooms. This diagnosis on site shows that the furniture and the building materials contribute equally to the indoor concentration in FA. The increase of the emissions is clearly influenced by the rise in the temperature. A balance mass model based on the measured emission rates led to a satisfying prediction of the FA concentrations in the 24 sampled rooms. The second axis deals with the analysis of the chemical profiles of 60 residences. From a “screening” of the VOC; homogeneous classes of chemical profiles associated with the dwellings could be established. Assumptions on the potential sources of these compounds were formulated and examined on the basis of the bibliography, the descriptive questionnaires of the dwellings and the emissions of materials and products present in indoor environment

Identification des sources intérieures de composés organiques volatils et estimation de leur contribution aux teneurs observées dans les logements français

Les atmosphères intérieures se révèlent très riches en composés organiques volatils (COV). Ces substances forment un cocktail à risque dont la composition et les effets sur la santé restent encore méconnu. Cette complexité rend difficile l identification et la quantification des sources intérieures sur la qualité de l air. Cette thèse a pour but d établir des relations qualitatives et quantitatives entre les sources intérieures de COV et les teneurs observées dans des logements français. Le premier axe de travail porte sur le développement de la mesure passive pour déterminer les taux d émission en formaldéhyde (FA) et en acétaldéhyde des matériaux. Ce préleveur a été validé en laboratoire, puis utilisé in-situ, dans une campagne de mesures réalisée dans des chambres étudiantes. Ce diagnostic sur site montre que le mobilier et les matériaux du bâti de la pièce contribuent à part égale à la concentration intérieure en FA. L augmentation des émissions est clairement influencée par l élévation de la température. Un modèle d équilibre des masses basé sur les taux d émission mesurés a conduit à une prédiction satisfaisante des concentrations en FA dans les 24 lieux échantillonnés. Le second axe porte sur l analyse des profils chimiques de 60 logements. A partir d un screening des COV ; des classes homogènes de profils chimiques associés aux logements ont pu être établies. Des hypothèses sur les sources potentielles de ces composés ont été formulées et examinées sur la base des données de la littérature, des questionnaires descriptifs des logements et des émissions de matériaux et produits présents en environnement intérieur.Indoor atmospheres appear very rich in volatile organic compounds (VOC). These substances form a dangerous mix whose composition and effects on health remain still unknown. This complexity makes difficult the identification and the quantification of indoor sources on the indoor air quality. The purpose of this thesis is to establish qualitative and quantitative relationship between VOC indoor sources and the concentrations observed in French dwellings. The first axis of this work deals with the development of passive measurement to determine the formaldehyde (FA) and acetaldehyde emission rates of materials. This sampler was validated in laboratory, then used in-situ, in a batch of measurements carried out in student rooms. This diagnosis on site shows that the furniture and the building materials contribute equally to the indoor concentration in FA. The increase of the emissions is clearly influenced by the rise in the temperature. A balance mass model based on the measured emission rates led to a satisfying prediction of the FA concentrations in the 24 sampled rooms. The second axis deals with the analysis of the chemical profiles of 60 residences. From a screening of the VOC; homogeneous classes of chemical profiles associated with the dwellings could be established. Assumptions on the potential sources of these compounds were formulated and examined on the basis of the bibliography, the descriptive questionnaires of the dwellings and the emissions of materials and products present in indoor environment.LILLE1-Bib. Electronique (590099901) / SudocSudocFranceF

Evidence of indoor sinks for formaldehyde through the field measurements using passive flux sampler and mass balance

International audienceA measurement campaign was conducted in 24 student rooms where formaldehyde emissions from all the indoor surfaces were measured using a passive flux sampler (PFS) parallel to monitoring of indoor and outdoor concentrations as well as the assessment of air exchange rate. Two mass balance models were used to predict indoor concentrations basing on input data recorded during this measurement campaign. The first model only takes into account the total emission from the indoor sources and the incoming and outgoing flows of compound brought by the air exchange rate. The second model added to these terms a further component related to the overall rate of removal processes (or “indoor sinks”) which was assessed in these same rooms during a previous field test campaign. A good agreement was found between the concentrations calculated by the model with the component relative to indoor removal processes and the measured concentrations. On the other hand, the predicted concentrations with a first model tend to highly overestimate the measured concentrations by a factor 1.9 on average. Apportionment of formaldehyde inputs and losses in the rooms was estimated and discussed. The results highlighted that indoor removal processes are a component to consider for formaldehyde budget indoors

Epoxiconazole exposure affects terpenoid profiles of oilseed rape plantlets based on a targeted metabolomic approach

Epoxiconazole is a broad-spectrum fungicide described as highly persistent in soil and as such can be considered as an abiotic agent like other problematic agrochemicals. Furthermore, the plant phenotyping tool involving non-invasive monitoring of plant-emitted volatile organic compounds (VOCs) may be useful in the identification of metabolic markers for abiotic stress. We therefore decided to profile the VOCs from secondary metabolism of oilseed rape through a dose-response experiment under several epoxiconazole concentrations (0, 0.01, 0.1 and 1 mg L−1). VOC collections of 35-day-old whole plantlets were performed through a dynamic headspace sampling technique under defined and controlled conditions. The plantlets grew freely within a home-made, laboratory and high-throughput glass chamber without any disturbance. Putative metabolic markers were analysed using a targeted metabolomic approach based on TD-GC-MS method coupled with data acquisition in SIM mode in order to focus on terpenes and sulphur-containing volatiles. Chromatograms of emitted terpenes were achieved accurately for the 35-day-old oilseed rape plantlets. We also analysed the presence of sulphur-containing volatiles in samples of shoot and root tissues using an innovative DHS-TD-GC-MS method, but no difference was found between qualitative profiles. Nevertheless, we demonstrated through this experiment that sesquiterpenes such as β-elemene and (E,E)-α-farnesene are involved in epoxiconazole dose-response. In particular, (E,E)-α-farnesene could serve as a metabolic marker of fungicide exposure for oilseed rape plantlets

How cadmium affects the fitness and the glucosinolate content of oilseed rape plantlets

Secondary metabolites such as glucosinolates (GSLs) are involved in plant response to biotic stress but can be significantly influenced by abiotic factors as well. Oilseed rape (Brassica napus L.) produces large quantities of several GSLs both in seeds and at the vegetative stage. These sulfur-containing compounds are known to play an important role in cadmium stress tolerance within the Brassicaceae family probably due to specific cross-talk between the S primary and secondary metabolism. Sulfur assimilation is in the middle of multiple metabolic pathways including Cd stress responses at physiological level. Our research focused on the assessment of GSL profiles and content in the roots and shoots of 28-day-old winter oilseed rape plantlets. The study was conducted under in vitro sterile conditions using concentration gradients of 0, 5, 15 and 45 µM of cadmium. A phenotypic analysis was carried out at the end of this experiment in order to evaluate the plantlets’ fitness. Our results described hormetic growth curves for root elongation, root biomass and shoot biomass at Cd concentrations of 5 µM and 15 µM respectively. Our experiment shows that a concentration of 5 µM can be considered as non-toxic, while one of 45 µM represents a lethal dose. Strong relationships were found between Cd accumulated in roots or translocated to shoots and the total sulfur accumulation in the plantlets’ different organs. A decrease of both indole and aliphatic GSL content associated with an increase of Cd accumulation and an increase of total sulfur accumulation was observed in the roots and shoots of the plantlets. It was also further demonstrated that Cd stress has a highly significant effect on roots’ and shoots’ GSL content bringing new insights into GSL’s possible role in the priming of Cd stress

Could indolic glucosinolates root profiling be correlated to Brassica napus L. cadmium stress tolerance?

Glucosinolates profiling among Brassicaceae and Brassica napus L. especially is largely studied regarding biotic stress. Nevertheless literature review could lead to suppose that theses secondary metabolites hugely produced within Brassicaceae family can interact in regards to cadmium stress as well. Sulfate primary metabolism plays an important role to Brassica napus L. cadmium stress tolerance and glucosinolates could serve as sulfate pool under such stress conditions. We describe here an in vitro experiment performed under sterile and controlled conditions showing the relationship between Brassica napus L. var. Es Astrid tolerance to a low concentration of cadmium and a decrease of a major indolic glucosinolates produced by the roots of this variety. Phenotyping results obtained from these cadmium stress conditions confirm also that Brassica napus L. remains a highly cadmium tolerant species probably due to glucosinolates root metabolism particularly

Using phenotyping and complementary VOC profiling approach to investigate physiological response of Brassica napus L. plantlets under cadmium and epoxiconazole abiotic stresses

Thanks to a laboratory, high-throughput and sterile homemade glass chambers system giving us the capacity to follow VOC (Volatile Organic Compounds) emissions at any time during plant growth, we are able to compare the phenotype of the plant and its VOC emission in the same time. Although the system could be used for biotic stress too, we decided to investigate the physiological response of oilseed rape plantlets such as model plant concerning two atypical abiotic stresses: cadmium and epoxiconazole. Experiments were achieved under several concentrations corresponding to a gradient from a tolerant to a sublethal dose. Oilseed rape plantlets phenotyping consisted in daily symptoms observation (chlorosis for cadmium stress and shorter internodes length for expoxiconazole stress), shoots and roots length recording and finally, fresh and dry weight assessment. The main goal was therefore to analyse VOC profile with a non-destructive method in parallel to this phenotype characterization in absence of interferences with uncontrolled environmental conditions. Cadmium was chosen because it can be problematic within agricultural soils (phosphate fertilizers among other things) and epoxiconazole because it is a systemic fungicide used in cereals known to be hugely persistent into agricultural soils.Solindi