Interactions between metals and soil organic matter in various particle size fractions of soil contaminated with waste water

Only scarce field studies concern the consequences of natural soil organic matter (SOM) and metal interactions on SOM dynamics in soils. We investigated the interactions of four metals (Pb, Zn, Cu and Cd) with the SOM associated to five different size fractions (between 2000 μm and b2 μm) of a sandy top soil contaminated by waste water. Metal, organic carbon and nitrogen concentrations were measured and chemical extractions (with Na4P2O7 and EDTA) were also performed to assess the variations of SOM–metal interactions irrespective of the size fraction. In addition, as in that selected contaminated site, maize (C4 plant), replaced C3 crops 15 years ago, natural isotopic 13C labelling gave new insights into SOM turnover. First, the results suggest that metals influence the SOM dynamics in that sandy soil: a C3 "old carbon" enrichment was observed in the small or clay size fractions, while the "new" C4 carbon associated with sandy soil particles presents a rapid turnover. Metal accumulation in the clay fraction is attributed to particulate organic matter (poorly associated) and SOM decay which overtime accumulated metals and eventually these metal–SOM associations prevent the biological decomposition of such carbon pools. Moreover, the δ13C signals, C/N ratios and results from chemical extractions clearly showed differences in the origin, nature and reactivity of the SOM as a function of the size fraction with consequences on the metal behaviour. Differences were observed between metals studied: Zn seems to be mainly bound to SOM associated with clay particles, while Pb seems to prefer to interact directly with the mineral surfaces versus the SOM

Etude d'évaluation du risque de mobilité des métaux dans l'agrosystème contaminé de Pierrelaye-Bessancourt : prospections du site, fonctionnement des sols et tests de lixiviation.

Ce sont les mécanismes de fixation et de libération des métaux dans ces sols pollués qui ont été approchés. Dans ce sens, l'étude se veut un outil d'aide à la décision pour les aménagements futurs du territoire. 1- Les de structures polygonales reconnues par géophysique conditionnent les modes et lieux d'infiltration des eaux. 2- L'irrigation a conduit à la déstabilisation des argiles des sols qui de ce fait ne jouent plus le rôle de rétention. Toutes les phases porteuses de métaux sont plus ou moins directement liées aux anciennes conditions d'hydromorphie (irrigation). L'arrêt de l'irrigation va déstabiliser progressivement ces complexes porteurs et libérer métaux retenus. 3- Des antibiotiques ont été mis en évidence dans les sols. Ils sont susceptibles d'agir sur les microorganismes des sols, et de ce fait présenter des risques environnementaux. 4- Les tests de lixiviation (lessivage/mobilisation) montrent la sensibilité des métaux à l'acidification du milieu et à l'oxydation de la matière organique. En raison de l'arrêt de l'irrigation il y aura accélération de la migration des métaux. 5- Les options de réaménagement sont discutées sous le regard sols/paysages : (1) en cas de boisement, l'acidification entraînera leur évacuation ; (2) les sols en place génèrent des poussières (dispersion dans l'environnement et inhalation humaine) ; (3) La dispersion incontrôlée des terres lors de terrassements est certainement un risque majeur

Etude en sciences sociales de grandes expéditions naturalistes contemporaines françaises,

social studies of sciences; Biodiversity inventories; systematicsInternational audienceCet article présente le projet de recherche interdisciplinaire, Expebiodiv visant à réaliser une étude interdisciplinaire des expeditions naturalistes contemporaines. Le cas étudié est celui du projet "La planète revisitée" qui est lancé pour 10 ans par le Museum d'Histoires Naturelle de Paris et l'ONG Pronatura International

doi:10.1016/j.envpol.2007.06.054

Kinetically defined metal fractions mimic mobility aspects of heavy metals. Abstract Kinetic EDTA and citrate extractions were used to mimic metal mobilization in a soil contaminated by metallurgical fallout. Modeling of metal removal rates vs. time distinguished two metal pools: readily labile (Q M1 ) and less labile (Q M2 ). In citrate extractions, total extractability (Q M1 þ Q M2 ) of Zn and Cd was proportionally higher than for Pb and Cu. Proportions of Pb and Cu extracted with EDTA were three times higher than when using citrate. We observed similar Q M1 /Q M2 ratios for Zn and Cu regardless of the extractant, suggesting comparable binding energies to soil constituents. However, for Pb and Cd, more heterogeneous binding energies were hypothesized to explain different kinetic extraction behaviors. Proportions of citrate-labile metals were found consistent with their short-term, in-situ mobility assessed in the studied soil, i.e., metal amount released in the soil solution or extracted by cultivated plants. Kinetic EDTA extractions were hypothesized to be more predictive for long-term metal migration with depth

Early impacts of marginal land-use transition to Miscanthus on soil quality and soil carbon storage across Europe

The authors acknowledged INA laboratories for performing soil chemical analysis, in particular Slijepčević Boris and Rukavina Slavica.Peer reviewe

The surface protein HvgA mediates group B streptococcus hypervirulence and meningeal tropism in neonates

Lethal meningitis triggered by the hypervirulent group B streptococcus clone ST-17 is mediated by a novel surface protein called HvgA

Routine molecular profiling of cancer: results of a one-year nationwide program of the French Cooperative Thoracic Intergroup (IFCT) for advanced non-small cell lung cancer (NSCLC) patients.

International audienceBackground: The molecular profiling of patients with advanced non-small-cell lung cancer (NSCLC) for known oncogenic drivers is recommended during routine care. Nationally, however, the feasibility and effects on outcomes of this policy are unknown. We aimed to assess the characteristics, molecular profiles, and clinical outcomes of patients who were screened during a 1-year period by a nationwide programme funded by the French National Cancer Institute. Methods This study included patients with advanced NSCLC, who were routinely screened for EGFR mutations, ALK rearrangements, as well as HER2 (ERBB2), KRAS, BRAF, and PIK3CA mutations by 28 certified regional genetics centres in France. Patients were assessed consecutively during a 1-year period from April, 2012, to April, 2013. We measured the frequency of molecular alterations in the six routinely screened genes, the turnaround time in obtaining molecular results, and patients' clinical outcomes. This study is registered with ClinicalTrials.gov, number NCT01700582. Findings 18 679 molecular analyses of 17 664 patients with NSCLC were done (of patients with known data, median age was 64·5 years [range 18–98], 65% were men, 81% were smokers or former smokers, and 76% had adenocarcinoma). The median interval between the initiation of analysis and provision of the written report was 11 days (IQR 7–16). A genetic alteration was recorded in about 50% of the analyses; EGFR mutations were reported in 1947 (11%) of 17 706 analyses for which data were available, HER2 mutations in 98 (1%) of 11 723, KRAS mutations in 4894 (29%) of 17 001, BRAF mutations in 262 (2%) of 13 906, and PIK3CA mutations in 252 (2%) of 10 678; ALK rearrangements were reported in 388 (5%) of 8134 analyses. The median duration of follow-up at the time of analysis was 24·9 months (95% CI 24·8–25·0). The presence of a genetic alteration affected first-line treatment for 4176 (51%) of 8147 patients and was associated with a significant improvement in the proportion of patients achieving an overall response in first-line treatment (37% [95% CI 34·7–38·2] for presence of a genetic alteration vs 33% [29·5–35·6] for absence of a genetic alteration; p=0·03) and in second-line treatment (17% [15·0–18·8] vs 9% [6·7–11·9]; p<0·0001). Presence of a genetic alteration was also associated with improved first-line progression-free survival (10·0 months [95% CI 9·2–10·7] vs 7·1 months [6·1–7·9]; p<0·0001) and overall survival (16·5 months [15·0–18·3] vs 11·8 months [10·1–13·5]; p<0·0001) compared with absence of a genetic alteration. Interpretation Routine nationwide molecular profiling of patients with advanced NSCLC is feasible. The frequency of genetic alterations, acceptable turnaround times in obtaining analysis results, and the clinical advantage provided by detection of a genetic alteration suggest that this policy provides a clinical benefit