The introduction of glyphosate-tolerant (GT) crops is expected to mitigate the environmental contamination by herbicides because glyphosate is less persistent and toxic than the herbicides used on non-GT crops. Here, we compared the environmental balances of herbicide applications for both crop types in three French field trials. The dynamic of herbicides and their metabolites in soil, groundwater and air was simulated with PRZM model and compared to field measurements. The associated impacts were aggregated with toxicity potentials calculated with the fate and exposure model USES for several environmental endpoints. The impacts of GT systems were lower than those of non-GT systems, but the accumulation in soils of one glyphosate metabolite (aminomethylphosphonic acid) questions the sustainability of GT systems. The magnitude of the impacts depends on the rates and frequency of glyphosate application being highest for GT maize monoculture and lowest for combination of GT oilseed rape and non-GT sugarbeet crops. The impacts of herbicide applications on glyphosate-tolerant crops could be higher than expected due to the accumulation of a metabolite of glyphosate in soils.

Diffuse pollution is a major cause for the degradation of water quality also in the French context. Nitrates and pesticides, mostly from agricultural sources, are the main pollutants. To a lesser extent, diffuse pollution has domestic and collective sources. Nitrate rates remain high in surface waters, despite an improvement of water quality in areas where livestock farming is responsible for nitrate pollution. The contamination of groundwater by nitrates and pesticides has been worsening in the last years. The EU Nitrate Directive is the main regulatory tool for the control of nitrate diffuse pollution. Farmers in designated vulnerable zones have to comply with measures included in action programs. The implementation of the ND in France was evaluated as incomplete relating to insufficient designation of vulnerable zones and non-conformity of action programs. Two other constraints are a low awareness of requirements by farmers and difficulties in controlling and enforcing compliance. As a consequence, the implementation process of the ND was redefined in France, with an extension of vulnerable zones, now covering 55% of agricultural area. While action programs were mainly defined at the district level, now a core program defined at the national level is completed by regional programs established by State regional authorities on the basis of the work of regional technical groups. The development of action plans to protect drinking water catchments relies on cooperation between water suppliers and agricultural stakeholders. A first step is the definition of protection zone(s) in the water catchment. Then, agricultural and non-agricultural pressures are identified. Finally, an action plan is defined to be implemented voluntary by farmers. In the French context, the involvement of water suppliers is fostered by financial incentives provided by Water Agencies. Also the “Grenelle” regulation imposes the definition and implementation of action plans in priority water catchments. The participation of farmers is targeted by a number of tools: (1) mostly agri-environmental schemes funded by EU rural development policy, (2) environmental land leases, (3) the development of market outlets such as local organic supply chains. Research shows that the success of this approach depends on a number of factors. The main success factors identified are: The scale of collective action. With regard with the governance of collective action, the definition of the role of stakeholders involved the involvement of farm leaders and farm organizations and the involvement of agricultural cooperatives and agro-industries. Finally, technical support to local stakeholders (water suppliers, farmers) was identified as a crucial success factor.

In France, the number of PDA quickly increases in order to better protect receiving surface water bodies. Setting up design rules and maintenance guidelines is now urgent. | En France, l'installation de ZRV en vue de protéger davantage le milieu récepteur de surface est désormais fréquente. L'élaboration de règles de dimensionnement et de maintenance est désormais urgente.

[Departement_IRSTEA]Territoires [TR1_IRSTEA]DTAM [Axe_IRSTEA]DTAM2-ACPUB | International audience | Diffuse pollution is a major cause for the degradation of water quality also in the French context. Nitrates and pesticides, mostly from agricultural sources, are the main pollutants. To a lesser extent, diffuse pollution has domestic and collective sources. Nitrate rates remain high in surface waters, despite an improvement of water quality in areas where livestock farming is responsible for nitrate pollution. The contamination of groundwater by nitrates and pesticides has been worsening in the last years. The EU Nitrate Directive is the main regulatory tool for the control of nitrate diffuse pollution. Farmers in designated vulnerable zones have to comply with measures included in action programs. The implementation of the ND in France was evaluated as incomplete relating to insufficient designation of vulnerable zones and non-conformity of action programs. Two other constraints are a low awareness of requirements by farmers and difficulties in controlling and enforcing compliance. As a consequence, the implementation process of the ND was redefined in France, with an extension of vulnerable zones, now covering 55% of agricultural area. While action programs were mainly defined at the district level, now a core program defined at the national level is completed by regional programs established by State regional authorities on the basis of the work of regional technical groups. The development of action plans to protect drinking water catchments relies on cooperation between water suppliers and agricultural stakeholders. A first step is the definition of protection zone(s) in the water catchment. Then, agricultural and non-agricultural pressures are identified. Finally, an action plan is defined to be implemented voluntary by farmers. In the French context, the involvement of water suppliers is fostered by financial incentives provided by Water Agencies. Also the “Grenelle” regulation imposes the definition and implementation of action plans in priority water catchments. The participation of farmers is targeted by a number of tools: (1) mostly agri-environmental schemes funded by EU rural development policy, (2) environmental land leases, (3) the development of market outlets such as local organic supply chains. Research shows that the success of this approach depends on a number of factors. The main success factors identified are: The scale of collective action. With regard with the governance of collective action, the definition of the role of stakeholders involved the involvement of farm leaders and farm organizations and the involvement of agricultural cooperatives and agro-industries. Finally, technical support to local stakeholders (water suppliers, farmers) was identified as a crucial success factor.

Physicochemical and biological characterisation of different dredged sediment deposit sites in France

[Departement_IRSTEA]MA [TR1_IRSTEA]QSA / HYDRECO | International audience | Scats of the European otter (Lutra lutra) were sampled along the Allier river (France) catchment for organochlorine toxic compounds (nine pesticides and 16 PCBs congeners) measurement. From early 2004 to June 2005, 90 sites of 40 rivers were twice investigated, and 71 scats samples collected, in four geographical areas being naturally re-colonized by the species since its legal protection. Detectable pesticides and PCBs were found in 100% of the samples. Mean values reached 2.72 and 13.58 mg kg-1 (lipid weight) for pesticides and PCBs, respectively. Amounts were significantly different between the four areas investigated. A significant increase in medium and absolute values is noted by going downstream of the catchment. Potential medium- and long-term consequences on the observed population increase are discussed.

Mosses are useful, ubiquitous accumulation biomonitors and as such can be used for biomonitoring surveys. However, the biomonitoring of atmospheric pollution can be compromised in urban contexts if the targeted biomonitors are regularly disturbed, irregularly distributed, or are difficult to access. Here, we test the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled mosses growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. We focused on Grimmia pulvinata (Hedwig) Smith, a species abundantly found in all studied cemeteries and very common in Europe. The concentration of Al, As, Br, Ca, Ce, Cl, Cr, Cu, Fe, K, Mn, Ni, V, P, Pb, Rb, S, Sr, Ti, and Zn was determined by a total reflection X-ray fluorescence technique coupled with a slurry sampling method (slurry-TXRF). This method avoids a digestion step, reduces the risk of sample contamination, and works even at low sample quantities. Elemental markers of road traffic indicated that the highest polluted cemeteries were located near the highly frequented Parisian ring road and under the influence of prevailing winds. The sites with the lowest pollution were found not only in the peri-urban cemeteries, adjoining forest or farming landscapes, but also in the large and relatively wooded cemeteries located in the center of Paris.Our results suggest that (1) slurry-TXRF might be successfully used with moss material, (2) G. pulvinata might be a good biomonitor of trace metals air pollution in urban context, and (3) cemetery moss sampling could be a useful complement for monitoring urban areas. Graphical abstract We tested the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled 110 moss cushions (Grimmia pulvinata) growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. The concentration of 20 elements in mosses was determined by a total reflection X-ray fluorescence technique coupled with a slurry sampling method. Statistical analysis revealed that: - Urbanized Parisian areas crossed by traffic roads have the highest polluted cemeteries with a strong influence of main wind direction on the distribution of air pollutants - As expected, small cemeteries with low tree density were heavily polluted - Less obvious, large green spaces such as large cemeteries (Père Lachaise, Montmartre, Montparnasse) in the center of a dense metropolis like Paris present the same level of atmospheric trace metal pollution as cemeteries in less urbanized areas or nearing a very large forest.This suggests that even in densely urbanized areas, there is more spatial variability in pollution distribution than usually assumed and that large urban areas with low traffic and green filters such as trees are likely to intercept air pollutants.

Dans le cadre du Programme national, d'étude des " Charges critiques en métaux lourds dans les sols ", animé par l'ADEME, on a cherché à décrire, dans deux écosystèmes pédologiques contrastés, les stocks et les flux de métaux (Zn, Pb, Cu, Ni, Cr) afin d'effectuer un état des lieux exhaustif de la distribution verticale des éléments traces métalliques (ETM) dans des profils de sol (solum). Ces sols, choisis en milieu forestier et éloignés de sources potentielles de pollutions, n'ont reçu que des retombées atmosphériques diffuses d'ETM. Les résultats montrent un fonctionnement actuel accumulateur pour le sol volcanique (andosol) vis-à-vis de tous les ETM étudiés. Le sol sableux (podzol) montre un fonctionnement actuel lixiviant. La démarche, qui combine l'utilisation des rapports isotopiques du plomb et d'un élément endogène de référence, le scandium, a permis de quantifier les distributions de plomb endogène et exogène, et par conséquent de préciser l'incorporation dans le sol du plomb atmosphérique. Dans les deux sols, le plomb est majoritairement exogène dans l'horizon de surface mais il migre en partie profondément, jusqu'à plus de 2 mètres. Un suivi de la contamination atmosphérique diffuse des écosystèmes devrait bénéficier de notre démarche en l'appliquant au Réseau national de mesures de la qualité des sols (RMQS)

En 1997, le ministere de l'Amenagement du Territoire et de l'Environnement et l'Agence de l'environnement et de la maitrise se de l'energie (ADEME) ont commande au Laboratoire de Glaciologie et Geophysique de l'environnement de Grenoble (LGGE) (CNRS) une etude visant a evaluer les depots de metaux lourds dans les Alpes francaises en utilisant le manteau neigeux saisonnier comme piege des ces polluants pour les hivers 1997-1998 et 1998-1999. La neige est en effet un support interessant car elle ne permet pas d'interaction chimique avec les metaux. Contrairement aux mousses, ce support a donc l'avantage de permettre la determination du depot reel de ces metaux, parametre indispensable pour evaluer ulterieurement les niveaux superieurs aux charges critiques. Le domaine d'etude a ete delimite au massif alpin, car il fallait trouver un domaine de montagne ou l'on avait des altitudes suffisamment elevees (1500m) pour obtenir un manteau neigeux consequent pendant une assez longue periode. De plus, la region Rhone-Alpes est dotee de vallees fortement industrialisees, avec un fort trafic routier, ce qui va permettre de suivre, entre autres, des polluants traceurs ainsi que leur repartition spatiale, et les niveaux de contamination des Alpes. L'etendue du domaine d'etude a, en revanche, ete etablie selon des criteres pratiques. L'integralite du massif Alpin francais n'etait pas gerable, meme avec l'aide des parcs nationaux, regionaux et des reserves naturelles. Nous avons donc prefere mettre l'accent sur des analyses et interpretations plus poussees au sein de chaque massif plutot que sur une plus grande quantite de mailles donc des echantillons. Dans cet article est presentee toute la methodologie mise en place pour le choix des sites, les prelevements, les analyses. Des premiers resultats sont presentes sur certains massifs