Interest and validation of early markers of environmental genotoxicity

Le présent projet propose de mettre au point des marqueurs biologiques de génotoxicité environnementale permettant une approche intégrée de la complexité des contaminations. Les préoccupations relatives aux pollutions des sols et des sédiments sont récentes. La contamination métallique des sols par exemple, due aux activités anthropiques est cependant préoccupante. Ce, en termes de risques pour la santé humaine et environnementale, du fait de la persistance, de l accumulation, et du transfert possible de ces métaux vers les nappes souterraines et vers les chaînes trophiques. Le projet de recherche porte sur la validation au laboratoire de marqueurs de génotoxicité, mis en œuvre sur plusieurs espèces représentatives en écotoxicologie terrestre, Eisenia fetida et Trifolium repens. Des travaux préliminaires, dans le cadre d un programme Ecotoxicité des sols contaminés par les éléments traces métalliques soutenu par l ANR et les FEDER, ont permis de mettre en évidence la pertinence du test des comètes avec Trifolium vis-à-vis des sols contaminées en éléments traces métalliques ou à des hydrocarbures en mélanges (lixiviats de déchet industriels). Le test des comètes (Single Cell Gel Electrophoresis Assay) permet la détection et la quantification des dommages à l ADN (cassures double et simple brin, sites alcali-labiles) au sein d une population cellulaire, induits par certains agents environnementaux. Il permet d évaluer l atteinte au génome d organismes modèles exposés. Cette atteinte de l ADN est une composante essentielle à estimer car elle contribue à l origine des phénomènes de cancérogenèse.This project proposes to develop biomarkers of environmental genotoxicity for an integrated approach to the complexity of the contamination. Concerns about pollution of soils and sediments are recent. Metal contamination of soils, for example, due to human activities, however, is worrying. This, in terms of risks to human health and environmental, because of the persistence, accumulation, and the possible transfer of these metals into groundwater and into food chains. The research project presented consists in the validation of laboratory markers of genotoxicity, implemented on several representative species in terrestrial ecotoxicology, Eisenia fetida and Trifolium repens. Preliminary work, as part of a program "Ecotoxicity of soils contaminated with trace elements" supported by the ANR and the ERDF, helped to highlight the relevance of the comet assay with Trifolium vis-à-vis Soil contaminated by trace metals or mixtures of hydrocarbons (industrial waste leachate). The comet assay (Single Cell Gel Electrophoresis Assay) allows detection and quantification of DNA damage (DNA double and single-stranded, alkali-labile sites) in a cell population, induced by certain environmental agents. It assesses the impairment of the genome of model organisms exposed. This DNA damage is an essential component to estimate because it contributes to the origin of the phenomena of carcinogenesis.LILLE1-Bib. Electronique (590099901) / SudocSudocFranceF

Contribution de l'écologie à la caractérisation de sites contaminés (application à l'évaluation des risques pour les écosystèmes)

LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

Bioaccumulation des métaux lourds chez Arrhenatherum elatius (L.) Beauv. Ex J. & C. Presl (implications pour la phytoremédiation)

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Etude d'un nouveau modèle biologique végétal (Trifolium repens) en écotoxicologie, applicable aux sols contaminés par les métaux lourds

En avril 2002, la commission européenne identifiait les différentes menaces pesant sur les sols, soulignant l importance des phénomènes de pollution de cette ressource non renouvelable. En France, un recensement des sites pollués fait apparaître qu il existe des situations considérées comme potentiellement à risque pour l environnement et la santé humaine. La gestion des sites pollués dépend étroitement de travaux de recherche destinés à caractériser au mieux la pollution en place et son évolution. Ces travaux de recherche sont nécessaires afin d'évaluer les possibilités de remédiation des sols. Ce suivi peut comporter différents aspects, parmi lesquels se distinguent des évaluations physicochimiques et biologiques. Il convient donc de développer des méthodes sensibles de diagnostic basées sur l utilisation de bio-indicateurs et de biomarqueurs. Les bio-indicateurs et les biomarqueurs sont des changements morphologiques, histologiques, physiologiques, biochimiques et moléculaires, spécifiques à des populations, observés après une exposition à un polluant. Un grand nombre de polluants environnementaux se retrouvant au niveau des sols, ont un pouvoir clastogène et aneugène important. Ils vont ainsi induire chez les organismes vivants des cassures ou des malségrégations chromosomiques non négligeables. Les végétaux supérieurs sont reconnus comme étant d excellents indicateurs des effets cytogénétiques ou mutagènes, provoqués par les contaminants. Ils seraient, de ce fait, utilisables en terme de biosurveillance pour la détection des substances mutagènes présentes dans l environnement. Ainsi, par l identification de biomarqueurs, et en particulier de biomarqueurs multifactoriels, nous avons étudié un nouveau modèle végétal (Trifolium repens) permettant d'estimer la toxicité des sols contaminés par les métaux lourds. L'étude de ce modèle a été réalisée à différents niveaux d'organisation biologique. La première partie de ces travaux concerne l'étude des différents bio-indicateurs et biomarqueurs suivis, avec la caractérisation de la symbiose bactérie/plante via la nodulation racinaire. L'étude des biomarqueurs du stress oxydant a été réalisée par le suivis d'enzymes intervenants dans l'élimination des espèces réactives de l'oxygène (APOX et GPOX). Enfin, nous avons adapté, le test des comètes, permettant d'estimer la formation de lésions primaires au niveau de l'ADN, chez ce modèle. A travers ces différents bioindicateurs et biomarqueurs, nous avons finalement caractérisé le comportement de Trifolium repens exposé à des sols provenant d'un secteur industriel fortement contaminé par les métaux lourds (Cd, Pb et Zn) et exposé à des sols contaminés par un lixiviat de déchets industriels banalsLILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

The comet assay in higher terrestrial plant model: Review and evolutionary trends

The comet assay is a sensitive technique for the measurement of DNA damage in individual cells. Although it has been primarily applied to animal cells, its adaptation to higher plant tissues significantly extends the utility of plants for environmental genotoxicity research. The present review focuses on 101 key publications and discusses protocols and evolutionary trends specific to higher plants. General consensus validates the use of the percentage of DNA found in the tail, the alkaline version of the test and root study. The comet protocol has proved its effectiveness and its adaptability for cultivated plant models. Its transposition in wild plants thus appears as a logical evolution. However, certain aspects of the protocol can be improved, namely through the systematic use of positive controls and increasing the number of nuclei read. These optimizations will permit the increase in the performance of this test, namely when interpreting mechanistic and physiological phenomena

Seasonal patterns of cadmium accumulation in Arrhenatherum elatius (Poaceae): Influence of mycorrhizal and endophytic fungal colonisation

International audienceWe investigated the influence of arbuscular mycorrhizae (AM) and dark septate fungi (DSF) colonisation on cadmium (Cd) accumulation in Arrhenatherum elatius from heavy metal-contaminated sites. AM colonisation disappeared when Cd concentrations in soil increased, while DSF infection was weak but constant throughout the experiment indicating that soil heavy metals are toxic to AM but not to DSF. AM colonisation was greatest when plant Cd concentrations were highest providing evidence that AM colonisation may influence Cd accumulation. In addition, the disappearance of AM and the concomitant reduction of Cd in shoots during seed maturation result in our suggestion that seasonal variation in AM may play a role in protecting developing seeds from soil pollution

Spatialized composite indices to evaluate environmental health inequalities: Meeting the challenge of selecting relevant variables

ACLThe wide range of factors involved in environmental health and the complexity of interactions between all environmental determinants require the validation of multidimensional approaches. While the development of composite indices is receiving growing attention by scientists and public authorities, the concept continues to lack transposability and robustness partly due to varying conceptualizations and/or methodologies. This review aims to promote harmonizing practices governing the first step of development of composite index, namely identification and characterization of the dimensions and variables that are included in environmental health indices. A review of available literature (more than 1500 studies) was conducted to identify the composite indices developed to assess territorial determinants from an environmental health perspective. This process made it possible to identify 23 spatialized composite indices and to assess a total of 329 variables. This diversity highlights that the absence of a common framework can lead to a strong subjectivity and limit comparisons between different environmental health indices. The specificity and the availability of certain variables would limit the transposability of indices. In light of current knowledge, this review proposes a consolidated methodological framework based on a categorization of variables into dimensions and sub-dimensions related to heath, environment, social, economics, services and policy. To characterize the sub-dimensions, several variables are possible and can be chosen according to the availability and/or accessibility of the data. The adaptation of a composite index to a specific territory or to a specific issue would then be effective through the included variables. This also aims to be transposable to any spatial unit (country, region, census tract). This work is a first step towards a proposal of guidelines designed to provide a consensual framework that could facilitate the exploitation of environmental health indices. This transparency could also increase the understanding and adoption of these tools by public authorities and general public

Mapping end-stage renal disease (ESRD): spatial variations on small area level in northern France, and association with deprivation.

Strong geographic variations in the incidence of end-stage renal disease (ESRD) are observed in developed countries. The reasons for these variations are unknown. They may reflect regional inequalities in the population's sociodemographic characteristics, related diseases, or medical practice patterns. In France, at the district level, the highest incidence rates have been found in the Nord-Pas-de-Calais region. This area, with a high population density and homogeneous healthcare provision, represents a geographic situation which is quite suitable for the study, over small areas, of spatial disparities in the incidence of ESRD, together with their correlation with a deprivation index and other risk factors.The Renal Epidemiology and Information Network is a national registry, which lists all ESRD patients in France. All cases included in the Nord-Pas-de-Calais registry between 2005 and 2011 were extracted. Adjusted and smoothed standardized incidence ratio (SIR) was calculated for each of the 170 cantons, thanks to a hierarchical Bayesian model. The correlation between ESRD incidence and deprivation was assessed using the quintiles of Townsend index. Relative risk (RR) and credible intervals (CI) were estimated for each quintile.Significant spatial disparities in ESRD incidence were found within the Nord-Pas-de-Calais region. The sex- and age-adjusted, smoothed SIRs varied from 0.66 to 1.64. Although no correlation is found with diabetic or vascular nephropathy, the smoothed SIRs are correlated with the Townsend index (RR: 1.18, 95% CI [1.00-1.34] for Q2; 1.28, 95% CI [1.11-1.47] for Q3; 1.30, 95% CI [1.14-1.51] for Q4; 1.44, 95% CI [1.32-1.74] for Q5).For the first time at this aggregation level in France, this study reveals significant geographic differences in ESRD incidence. Unlike the time of renal replacement care, deprivation is certainly a determinant in this phenomenon. This association is probably independent of the patients' financial ability to gain access to healthcare

Between physicochemical characterization of atmospheric particles and their impact on human health - challenges and perspectives (RECORD project)

ACTNInternational audienc

Crohn's disease and environmental contamination: Current challenges and perspectives in exposure evaluation

ACLAlthough the incidence of Crohn’s disease has increased worldwide over the past 30 years, the disorder’s exact causes and physiological mechanisms have yet to be determined. Given that genetic determinants alone do not explain the development of Crohn’s disease, there is growing interest in “environmental” determinants. In medical science, the term “environment” refers to both the ecological and social surroundings; however, most published studies have focused on the latter. In environmental and exposure sciences, the term “environment” mostly relates to contamination of the biotope. There are many unanswered questions on how environmental hazards might contribute to the pathogenesis of Crohn’s disease. Which pollutants should be considered? Which mechanisms are involved? And how should environmental contamination and exposure be evaluated? The objective was to perform a systematic review of the literature on Crohn’s disease and environmental contamination. We searched the PubMed, Google Scholar, Scopus, ISI Web of Science and Prospero databases. We considered all field studies previous to April 2019 conducted on human health indicators, and evaluating exposure to all type of physical, biological and chemical contamination of the environment. The lack of clear answers to date can be ascribed to the small total number of field studies (n ¼ 16 of 39 publications, most of which were conducted by pioneering medical scientists), methodological differences, and the small number of contaminants evaluated. This make it impossible to conduct a coherent and efficient meta-analysis. Based on individual analysis of available studies, we formulated five recommendations on improving future research: (i) follow up the currently identified leads - especially metals and endocrine disruptors; (ii) explore soil contamination; (iii) gain a better knowledge of exposure mechanisms by developing transdisciplinary studies; (iv) identify the most plausible contaminants by developing approaches based on the source-to-target distance; and (v) develop registries and cohort-based analyse