Detection of Adsorbed Chlordecone on Microplastics in Marine Sediments in Guadeloupe: A Preliminary Study

Plastic pollution in the oceans is recognized as a worldwide problem. Since the 1950s, the production of plastics has been increasing and the first reports of microplastics (particles \u3c 500 μm) in the marine environment began to appear in the 1970s. These particles represent a growing environmental problem due to their dispersion in seawater and marine organisms. Additionally, microparticles in general can adsorb pollutants that will then become bioavailable to organisms by being desorbed during digestion, which could be an important pathway for the contamination of organisms. In Guadeloupe and Martinique, an organochlorine pesticide called “chlordecone” was used from 1972 to 1993 in banana plantations and this very persistent pollutant contaminates soils, rivers, and coastal marine areas and accumulates in marine foodwebs. To examine these issues, we had two goals: 1) to assess the contamination of marine sediments by microplastics surrounding Guadeloupe; and 2) to determine the ability of microplastics to adsorb chlordecone, as has been demonstrated for other organochlorine pollutants. To do so, marine sediments were collected in triplicate from 12 sites in coral reef environments around the island. Microplastics from each sample were then enumerated by size, color and shape under a binocular microscope. The results indicate that microplastics are found in all the studied sites and that their distribution could be linked to marine currents or proximity to areas of significant human activities (port activities, agglomeration, etc.). Finally, our preliminary results indicated that chlordecone could be adsorbed onto microplastics, with a concentration ranging from 0.00036—0.00173 µg/µg of microfilter

Évaluation écotoxicologique d’un polluant pharmaceutique d'intérêt émergent (le furosémide) et de ses produits de dégradation

Many drugs are consumed daily and then discharged into wastewater. However, wastewater treatment plants (WWTPs) are not designed to effectively eliminate these compounds, which are then released into the aquatic environment, thus representing a hazard for ecosystems. Among these pharmaceutical pollutants, some are very frequently found in surface water, as in the case of furosemide. It is one of the most widely used drugs in the world. Considered as an essential drug by the World Health Organization, it is a powerful loop diuretic widely prescribed to treat heart and kidney failure or hypertension. Highly consumed, persistent and poorly eliminated by WWTPs, furosemide is increasingly becoming a compound of emerging concern.Moreover, during its transfer to the environment, furosemide can be degraded into several by-products, which remain poorly characterized to date. The first part of this work aims to quantify two of them, also known as human metabolites, in the environment: Saluamine, known for a long time, and the recently discovered pyridinium of furosemide, possible inducer of neurodegenerative diseases, are indeed particularly concerning. A liquid chromatography-mass spectrometry method has been developed to quantify them. The analysis of different samples (EHPAD, STEU, river) showed for the first time their presence in the aquatic environment. In parallel, the degradation efficiency of furosemide by advanced treatment processes (UV/H2O2, chlorination, ozonation) has been evaluated in addition to the formation of new degradation products. Chlorination and ozonation were found to be very effective in removing furosemide but produce saluamine.Furosemide, saluamine and pyridinium, may therefore present a significant risk to non-target organisms. The second part of this thesis aims at evaluating their toxicity, at high and environmental concentrations, on representative models of an aquatic ecosystem (fish, daphnia, algae). Several bioassays were developed to evaluate acute toxicity, modification of functional traits, oxidative stress, or their impact on behavior. Our results show an effect, not only of degradation products, but also of furosemide at environmental concentrations. Moreover, a first approach on the cocktail effects was carried out on daphnids and shows a synergistic effect of these molecules.Saluamine and pyridinium being human metabolites, the third part of this study focuses on their impact on human liver, kidney and neuroblastoma cells. Acute toxicity tests also showed a greater effect of the by-products and the mixture compared to furosemide. Proteomic analyses were also performed to identify certain mechanisms of action through the expression of deregulated proteins.Finally, this work underlines the importance of better characterizing the degradation products during the risk assessment of a micropollutant, because they can be more toxic than their parent molecule. The multi-model approach is also relevant because of the different sensitivity of organisms to micropollutants. These results highlight the interest of studying cocktail effects, which are still poorly documented under environmental conditions. Many pharmaceutical compounds such as furosemide can have adverse effects on the ecosystem even at trace concentrations. It would then be interesting to include these compounds in the lists of monitored pollutants that are currently not taken into account at all in the regulations.De nombreux médicaments sont consommés quotidiennement et sont ensuite évacués dans les eaux usées. Cependant, les Stations de Traitement des Eaux Usées (STEU) ne sont pas conçues pour éliminer efficacement ces composés, qui sont alors rejetés dans l'environnement aquatique et représentent un danger pour les écosystèmes. Parmi ces polluants pharmaceutiques, certains sont très fréquemment retrouvés dans les eaux de surface: c’est notamment le cas du furosémide. C’est l'un des médicaments les plus utilisés dans le monde. Considéré comme un médicament essentiel par l'Organisation Mondiale de la Santé, c’est un puissant diurétique de l'anse largement prescrit pour traiter l'insuffisance cardiaque et rénale ou l'hypertension. Fortement consommé, persistant et peu éliminé par les STEU, le furosémide s’inscrit peu à peu comme un composé d'intérêt émergent.De plus, au cours de son transit vers l'environnement, le furosémide peut être dégradé en plusieurs sous-produits, qui sont encore très mal caractérisés. La première partie de ce travail a pour but de quantifier dans l’environnement deux d’entre eux, également connus comme métabolites humains : La saluamine, connue depuis longtemps, et le pyridinium du furosémide, récemment découvert, possible inducteur de maladies neurodégénératives sont en effet particulièrement préoccupants. Une méthode de chromatographie liquide couplée à de la spectrométrie de masse a été développée pour les quantifier. L’analyse de différents échantillons (EHPAD, STEU, rivière) a montré pour la première fois leur présence dans le milieu aquatique. En parallèle, l’efficacité de dégradation du furosémide par des procédés de traitement avancé (UV/H2O2, Chloration, Ozonation) a été évaluée en plus de la formation de nouveaux produits de dégradation. La chloration et l’ozonation se sont révélées très efficaces pour éliminer le furosémide mais produisent en revanche de la saluamine.Le furosémide, la saluamine et le pyridinium, peuvent donc présenter un risque important pour les organismes non cibles. La seconde partie de cette thèse a donc pour objectif d’évaluer leur toxicité, à des concentrations fortes et environnementales, sur des modèles représentatifs d’un écosystème aquatique (poisson, daphnie, algue). Plusieurs bioessais ont été développés afin d’évaluer la toxicité aiguë, la modification des traits fonctionnels, le stress oxydant, ou encore leur impact sur le comportement. Nos résultats montrent un effet, non seulement des produits de dégradation, mais également du furosémide dès les concentrations environnementales. De plus, une première approche sur les effets cocktails a été menée sur les daphnies et montre un effet synergique de ces molécules.La saluamine et le pyridinium étant des métabolites humains, la troisième partie de cette étude s'intéresse donc à leur impact sur les cellules humaines de foie, de rein et de neuroblastome. Des tests de toxicité aiguë montrent également un effet plus important des sous-produits et du mélange par rapport au furosémide. Des analyses protéomiques ont aussi été réalisées afin d’identifier certains mécanismes d’action au travers de l’expression de protéines dérégulées.Finalement, ces travaux soulignent l’importance de mieux caractériser les produits de dégradation lors de l'évaluation du risque lié à un micropolluant, car ils peuvent se révéler plus toxiques que leur molécule parent. L’approche multi-modèle est également pertinente du fait de la sensibilité différente des organismes aux micropolluants. Ces résultats mettent en lumière l’intérêt d'étudier les effets cocktails, à ce jour encore peu documentés dans les conditions environnementales. De nombreux composés pharmaceutiques comme le furosémide peuvent avoir des effets délétères sur l'écosystème même à des concentrations trace. Il serait alors intéressant d'intégrer ces composés aux listes de polluants suivis qui ne sont pour l’instant pas du tout pris en compte dans les réglementations

Évaluation des effets de perturbation endocrinienneinduits par un polluant pharmaceutique émergent et ses produits de dégradation chez Daphniamagna.

International audienc

Evaluation écotoxicologique d’un polluant pharmaceutique émergent : le Pyridinium du Furosémide (PoF)

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Ecotoxicological Study of an Emerging Pharmaceutical Pollutant: The Pyridinium of Furosemide (PoF)

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Proteomics approach for evaluating metabolites toxicity of furosemide, a widely-used diuretics.

Introduction. Pharmaceutical by-products (PPs) including metabolites and transformation products of pharmaceuticals are a lot of concerns for both human and ecosystems health. Several studies pointed out PPs as emerging pollutants with a risk of toxicity exceeding the one of their parent molecules. Herein, we used toxicoproteomics to unveil toxicity effects of PPs of furosemide, a widely used diuretics. PPs of interest are pyridinium of furosemide (PYR), saluamine (SAL) and furfural (FRF) that were recently revealed as potential emerging pollutants in water. Methods. A label-free proteomic approach and cell viability assays were performed on hepatocarcinoma Hep-G2 cell line exposed for 96h to PPs (PYR, SAL FRF), furosemide and their mixture (MIX) at a CL10 letal dose. Protein extracts were submitted to a trypsin/Lys-C enzymatic digestion before performing LC-MSE analysis by using a NanoAcquity-C18/SYNAPT-G2Si massspectrometer system. Results. Toxic effects were confirmed on Hep-G2 cell line with a higher toxicity after an exposure to PYR, SAL and FRF while more substantial toxic effects were observed after an exposure to MIX and FUR. Based on the quantification of 1379 proteins, wedeciphered 71, 101, 138, 205 and 34 deregulated proteins after exposure to FUR, PYR, SAL, FRF, and MIX, respectively. A gene ontology enrichment analysis revealed that these proteins were involved in metabolism, immune response, biosynthesis or oxidative stress. For PPs exposure (PYR/SAL/FRF), these proteins were related to several diseases (neurodegenerativediseases/endocrine disruption/cancer) while, for MIX, these diseases were not retrieved, suggesting possible antagonistic effects. Conclusions. This toxicoproteomic work contributes to improve the current understanding of furosemide by-products and their mixture impacts on human cells. Beyond the case of furosemide, our study underlined the need to better take into account drug by-products during toxicological risk assessment

Proteomics approach for evaluating metabolites toxicity of furosemide, a widely-used diuretics.

Introduction. Pharmaceutical by-products (PPs) including metabolites and transformation products of pharmaceuticals are a lot of concerns for both human and ecosystems health. Several studies pointed out PPs as emerging pollutants with a risk of toxicity exceeding the one of their parent molecules. Herein, we used toxicoproteomics to unveil toxicity effects of PPs of furosemide, a widely used diuretics. PPs of interest are pyridinium of furosemide (PYR), saluamine (SAL) and furfural (FRF) that were recently revealed as potential emerging pollutants in water. Methods. A label-free proteomic approach and cell viability assays were performed on hepatocarcinoma Hep-G2 cell line exposed for 96h to PPs (PYR, SAL FRF), furosemide and their mixture (MIX) at a CL10 letal dose. Protein extracts were submitted to a trypsin/Lys-C enzymatic digestion before performing LC-MSE analysis by using a NanoAcquity-C18/SYNAPT-G2Si massspectrometer system. Results. Toxic effects were confirmed on Hep-G2 cell line with a higher toxicity after an exposure to PYR, SAL and FRF while more substantial toxic effects were observed after an exposure to MIX and FUR. Based on the quantification of 1379 proteins, wedeciphered 71, 101, 138, 205 and 34 deregulated proteins after exposure to FUR, PYR, SAL, FRF, and MIX, respectively. A gene ontology enrichment analysis revealed that these proteins were involved in metabolism, immune response, biosynthesis or oxidative stress. For PPs exposure (PYR/SAL/FRF), these proteins were related to several diseases (neurodegenerativediseases/endocrine disruption/cancer) while, for MIX, these diseases were not retrieved, suggesting possible antagonistic effects. Conclusions. This toxicoproteomic work contributes to improve the current understanding of furosemide by-products and their mixture impacts on human cells. Beyond the case of furosemide, our study underlined the need to better take into account drug by-products during toxicological risk assessment

Contamination of marine sediments by microplastics and adsorbed organochlorine pollution (chlordecone) in coral reefs of Guadeloupe (Lesser Antilles)

International audienc

Detection of adsorbed chlordecone on microplastics in marine sediments in Guadeloupe: a preliminary study

International audiencePlastic pollution in the oceans is recognized as a worldwide problem. Since the 1950s, the production of plastics has been increasing and the first reports of microplastics (particles < 500 μm) in the marine environment began to appear in the 1970s. These particles represent a growing environmental problem due to their dispersion in seawater and marine organisms. Additionally, microparticles in general can adsorb pollutants that will then become bioavailable to organisms by being desorbed during digestion, which could be an important pathway for the contamination of organisms. In Guadeloupe and Martinique, an organochlorine pesticide called “chlordecone” was used from 1972 to 1993 in banana plantations and this very persistent pollutant contaminates soils, rivers, and coastal marine areas and accumulates in marine foodwebs. To examine these issues, we had two goals: 1) to assess the contamination of marine sediments by microplastics surrounding Guadeloupe; and 2) to determine the ability of microplastics to adsorb chlordecone, as has been demonstrated for other organochlorine pollutants. To do so, marine sediments were collected in triplicate from 12 sites in coral reef environments around the island. Microplastics from each sample were then enumerated by size, color and shape under a binocular microscope. The results indicate that microplastics are found in all the studied sites and that their distribution could be linked to marine currents or proximity to areas of significant human activities (port activities, agglomeration, etc.). Finally, our preliminary results indicated that chlordecone could be adsorbed onto microplastics, with a concentration ranging from 0.00036—0.00173 µg/µg of microfilter