The biodegradation of nonextractable residues (NER) of pesticides in soil is still poorly understood. The aim of this study was to evaluate the influence of NER ageing and fresh soil addition on the microbial communities responsible for their mineralisation. Soil containing either 15 or 90-day-old NER of C-13-2,4-D (NER15 and NER90, respectively) was incubated for 90 days with or without fresh soil. The addition of fresh soil had no effect on the mineralisation of NER90 or of SOM, but increased the extent and rate of NER15 mineralisation. The analyses of C-13-enriched FAME (fatty acids methyl esters) profiles showed that the fresh soil amendment only influenced the amount and structure of microbial populations responsible for the biodegradation of NER15. By coupling biological and chemical analyses, we gained some insight into the nature and the biodegradability of pesticide NER.

International audience | Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography-mass spectrometry could be correctly predicted by NIRS (Q² = 0.75, R² = 0.82 for the total set), especially for samples with chlordecone content <12 mg kg(-1) or when the sample set was rather homogeneous (Q² = 0.91, R² = 0.82 for the Andosols). Conventional measures and NIRS predictions were poorly correlated for chlordecone content >12 mg kg(-1), nevertheless ca. 80% samples were correctly predicted when the set was divided into three or four classes of chlordecone content. Thus NIRS could be considered a time- and cost-effective method for characterising soil contamination by chlordecone.

International audience | Community structure and microcystin accumulation of freshwater molluscs were studied before and after cyanobacterial proliferations, in order to assess the impact of toxic blooms on molluscs and the risk of microcystin transfer in food web. Observed decrease in mollusc abundance and changes in species richness in highly contaminated waters were not significant; however, relative abundances of taxa (prosobranchs, pulmonates, bivalves) were significantly different before and after cyanobacterial bloom. Pulmonates constituted the dominant taxon, and bivalves never occurred after bloom. Microcystin accumulation was significantly higher in molluscs from highly (versus lowly) contaminated waters, in adults (versus juveniles) and in pulmonates (versus prosobranchs and bivalves). Results are discussed according to the ecology of molluscs, their sensitivity and their ability to detoxify.

Correspondance auteur: P. Hinsinger e-mail: philippe.hinsinger@supagro.inra.fr | International audience | We evaluated how root-induced changes in rhizosphere pH varied and interacted with Cu availability and bioavailability in an acidic soil. Rape was grown on a Cu-contaminated acidic soil, which had been limed at 10 rates. Soil Cu bioavailability was not influenced by liming. However, liming significantly decreased CaCl2-extracted Cu for pH between 3.7 and 5.1. Little effect was found for pH above 5.1. For soil pH < 4.4, CaCl2-Cu contents were smaller in rhizosphere than uncropped soil. Rhizosphere alkalisation occurred at pH < 4.8, while acidification occurred at greater pH. This explained the changes of CaCl2-Cu in the rhizosphere at low pH and the absence of pH dependency of Cu bioavailability to rape. In addition, apoplastic Cu in roots increased with increasing soil pH, most probably as a result of increased dissociation and affinity of cell wall compounds for Cu

International audience | In the frame of a French monitoring program, tri- to deca- polybromodiphenylethers (PBDE) have been measured in maternal and cord serum, adipose tissue, and breast milk samples, collected from 93 volunteer women during caesarean deliveries. The seven major tri- to heptaBDE (BDE-28, 47, 99,100,153, 154, and 183) were detected in adipose tissue and breast milk with cumulated median values of 2.59 and 2.51 ng g(-1) lw. Nine highly brominated octa- to decaBDE (BDE-196, 197, 201, 202, 203, 206, 207, 208 and 209) was performed in the same samples, with cumulated median values of 2.73 and 3.39 ng g(-1) lw in adipose tissue and breast milk, respectively. At this opposite, median levels of octa- to decaBDE in maternal and cord serum appeared significantly higher than the levels of tri- to heptaBDE in the same matrices, i.e. 8.85 and 12.34 versus 0.98 and 0.69 ng g(-1) lw, respectively.

International audience | The ability of metallic nanoparticles to be oxidized, reduced or dissolved in biological media can be used to predict their toxicity in vitro. a b s t r a c t The level of production of nanoparticles will inevitably lead to their appearance in air, water, soils, and organisms. A theoretical framework that relates properties of nanoparticles to their biological effects is needed to identify possible risks to human health and the environment. This paper considers the properties of dispersed metallic nanoparticles and highlights the relationship between the chemical stability of these nanoparticles and their in vitro toxicity. Analysis of published data suggests that chemically stable metallic nanoparticles have no significant cellular toxicity, whereas nanoparticles able to be oxidized, reduced or dissolved are cytotoxic and even genotoxic for cellular organisms.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | Little information is available on the environmental occurrence and ecotoxicological effects of pharmaceutical gestagens released in the aquatic environment. Since eighteen different gestagens were found to be used in France, preliminary exposure and hazard assessment were done. Predicted environmental concentrations (PECs) suggest that if parent gestagens are expected to be found in the ng l−1 range, some active metabolites could be present at higher concentrations, although limited data on metabolism and environmental fate limit the relevance of PECs. The biological effects are not expected to be restricted to progestagenic activity. Both anti-androgenic activity (mainly for cyproterone acetate, chlormadinone acetate and their metabolites) and estrogenic activity (mainly for reduced metabolites of levonorgestrel and norethisterone) should also occur. All these molecules are likely to have a cumulative effect among themselves or with other xenoestrogens. Studies on occurrence, toxicity and degradation time are therefore needed for several of these compounds.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | Among the numerous PCB congeners, most of the dioxin-like PCBs (DL-PCBs) need to be characterized by hyphenated techniques. It has been shown in several instances that these congeners are well related to the total PCB content in fish.We examined datasets collected mainly in France, on freshwater and marine fish and sediments. A statistical model linking DL- and indicator PCBs was developed for a dataset composed of freshwater fishes, and proved to predict well DL-PCBs from indicator PCBs in all other fish sets, including marine ones. Type II error rates remained low in almost all fish sets. A similar correlation was observed in sediments. Non-dioxin-like PCBs elicit various adverse effects and represent 95% of the total PCBs. A European guideline for them is needed; the correlation between DL- and indicator PCBs could help develop this standard in the future.

National audience | Nowadays, promoted as a renewable energy, biomass burning becomes more and more widespread all over the world. In urban and rural areas biomass, mainly wood, is burned for heating, cooking, and waste disposal purposes. This biofuel seems to be an alternative to the rarefaction of the fossil fuel and, moreover it decreases the emission of carbon dioxide causing global warming. However, wood smoke contains various air pollutants such as fine particulate matter (PM10, PM2.5), polycyclic aromatic hydrocarbons (PAHs), benzene, dioxins... and in consequence has an impact on the air quality. In order to estimate the contribution of wood burning on the atmospheric organic aerosol of urban areas, the French ministry of environment (MEEDDAT), called upon this study during the winter 2006/2007, in the French cities of Grenoble, Lille, Strasbourg and Gennevilliers. For this work, different species have been looked after. The global characterization of the atmospheric aerosols has been made taking in account the PM10, the organic carbon (OC), and the elementary carbon (EC). Measurement of biomass burning tracers (levoglucosan, mannosan, and galactosan) has been undertaken, as well as methoxyphenols, which are more specific wood smoke tracers. The analyses of organic tracers by gas chromatography coupled with a mass spectrometer detector (GC/MS) show average concentrations of levoglucosan in the range of 272 ng.m-3 for Gennevilliers to 1 148 ng.m-3 for Grenoble. Mannosan and galactosan have also been measured in all cities but in lower quantities. The methoxyphenols have been detected only in rare occasions and at the limit of detection of the analytical method. PM10 measurements range from 20.6 micro g.m-3 for Gennevilliers to 35.8 micro g.m-3 for Grenoble. At the same time, OC values range from 3.61 micro g.m-3 to 11.15 micro g.m-3. Moreover high correlations have been observed between levoglucosan and OC, respectively 0.80 and 0.86 for Grenoble and Strasbourg. In addition, with respectively 10.98 ng.m-3 and 8.20 ng.m-3, Grenoble and Strasbourg present the highest particulate PAHs average concentrations of the four cities. All these results seem to indicate that Grenoble and Strasbourg are more impacted by the biomass burning than the two other cities. And more particularly in Grenoble where the organic aerosol fraction is very huge, this last phenomenon is typically characteristic of the biomass burning. To conclude, this study shows and confirms the usefulness of levoglucosan as biomass burning tracer and the difficulty to use methoxyphenols as woodsmoke tracers in ambient areas. | De nos jours, l'utilisation du bois en tant que combustible est relativement répandue en France et dans le monde entier. L'augmentation du prix du pétrole et des autres sources d'énergie épuisables va certainement engendrer dans les années à venir une contribution accrue du chauffage domestique au bois. L'utilisation de cette source d'énergie renouvelable pose cependant de nombreux problèmes sur la santé humaine. En effet, la fumée émise lors de la combustion du bois contient un certain nombre de composés polluants, tels que les hydrocarbures aromatiques polycycliques (HAP), le benzène, les fines particules (PM10, PM2,5)... Les émissions de la combustion du bois ont donc un impact sur la qualité de l'air. Cet impact peut être évalué par l'étude de traceurs organiques spécifiques de la combustion du bois identifiables au sein de la composante organique des aérosols. Ces traceurs sont des produits provenant de la combustion de la cellulose et de l'hémicellulose tels que le lévoglucosan, mannosan, galactosan et des composés issus de la thermodégradation de la lignine tels que les méthoxyphénols. Cette méthode a été appliquée à une étude commanditée à l'INERIS par le ministère de l'Écologie, de l'Énergie, du Développement Durable et de l'Aménagement du Territoire (MEEDDAT), en partenariat avec des Associations agréées de la surveillance de la qualité de l'air (AASQA). L'objectif était de caractériser l'influence de la combustion du bois sur la composante organique de l'aérosol atmosphérique en site urbain. Des prélèvements d'aérosols ont été effectués sur une période allant de novembre 2006 à avril 2007, dans quatre grandes villes de France : Grenoble, Lille, Strasbourg, et Gennevilliers. L'analyse par chromatographie gazeuse couplée à un spectromètre de masse (GC/MS) des traceurs organiques les plus stables, lévoglucosan, mannosan et galactosan, confirme l'influence de cette source sur la qualité de l'air des quatre villes. Sur la période d'étude, la concentration moyenne en lévoglucosan varie de 272 ng.m-3 pour la ville de Gennevilliers à 1 148 ng.m-3 pour la ville de Grenoble. La confrontation des résultats de ces traceurs avec les données usuelles de caractérisation de l'aérosol, telles que le carbone organique (OC) et le carbone élémentaire (EC), montre une participation du chauffage au bois plus importante dans les villes de Grenoble et de Strasbourg. Les résultats d'analyse du lévoglucosan obtenus sur la ville de Gennevilliers indiquent une très bonne corrélation avec les HAP particulaires et les PM10. Ces résultats prouvent que la combustion du bois joue un rôle important sur la composition de la matière organique de l'aérosol atmosphérique et sur la pollution particulaire en milieu urbain. En revanche, les méthoxyphénols ont été peu détectés sur les divers échantillons analysés.

In urban catchments, diffuse stormwater discharges from both separate and combined sewers contribute significantly to the contamination of water bodies by numerous pollutants, including the priority substances listed in the European Water Framework Directive. Whereas concentrations and loads of traditional pollutants (suspended solids, BOD, COD, nutriments) in stormwater discharges are well documented, very few information is available on the presence, the concentrations and the loads of priority substances. The ESPRIT project aims to identify, evaluate, characterise and later on model fluxes of priority pollutants in urban stormwater discharges. Two sites were chosen for measurement campaigns: Ecully (residential site, combined sewer) and Chassieu (industrial site, separate sewer). In total, 26 metals and 36 organic pollutants (in particulate and dissolved phases) are measured in stormwater discharges at the catchment outlets. Some results obtained for a set of rainfall events monitored since the beginning of 2008 are presented. Significant inter-site and inter-event variability in concentrations and specific fluxes (g/active ha) are observed for metals and organics pollutants, particularly for pesticides.