Laboratory leaching studies of oryzalin and diuron through three undisturbed vineyard soil columns

The leaching of diuron and oryzalin through undisturbed soil columns was studied in the laboratory using three vineyard soils from Vosne-Romanée (Burgundy): a rendosol, a calcosol and a vegetated calcosol. After 845 mm of simulated rainfall in 15 days, soil leachates contained higher amounts of diuron (3.2%, 11.8% and 18.8% of applied diuron, respectively) than oryzalin (0.2%, 4.9%, 3.7%, respectively). A greater proportion of soil extractable residues was obtained for diuron (42.5%, 26.8% and 32.2%, respectively) than for oryzalin (14.7%, 12% and 15.5%, respectively). The greater mobility of diuron might be related to its higher water solubility (36.4 mgl(-1) compared with 2.6 mgl(-1) for oryzalin) and smaller adsorption coefficient (400 lkg(-1), compared with 700-1100 lkg(-1) for oryzalin). The mobility of the two herbicides was greater in the two calcosols than in the rendosol, not only due to different organic carbon contents but also different soil textures and structures.     

Spatial distribution of pollution in an urban stormwater infiltration basin

Infiltration basins are frequently used for stormwater drainage. Because stormwater is polluted in highly toxic compounds, assessment of pollution retention by infiltration basins is necessary. Indeed, if basins are not effective in trapping pollution, deep soil and groundwater may be contaminated. This study's objective is to investigate soil pollution in infiltration basins: spatial distribution of soil pollution, optimisation of the number of soil samples and a contamination indicator are presented. It is part of a global project on long-term impact of stormwater infiltration on groundwater. Soil sampling was done on a basin in suburban Lyon (France). Samples were collected at different depths and analysed for nutrients, heavy metals, hydrocarbons and grain size. Pollutant concentrations decrease rapidly with depth while pH, mineralisation and grain size increase. Sustainable metal concentrations are reached at a 30-cm depth, even after 14 years of operation; hydrocarbon pollution is deeper. Principal component analysis shows how pollutants affect each level. The topsoil is different from other levels. Three specifically located points are enough to estimate the mass of pollution trapped by the basin with a 26% error. The proposed contamination indicator is calculated using either average level concentrations or maximum level concentrations. In both cases, the topsoil layer appears polluted but evaluation of lower levels is dependent on the choice of input concentrations.     

Trophic diversity of idoteids (Crustacea, Isopoda) inhabiting the Posidonia oceanica litter

The coexistence of three idoteid species in Posidonia oceanica litter raises the question of trophic diversity and their role in the litter degradation process. Hence, diet composition of Idotea balthica, Idotea hectica and Cleantis prismatica was studied using a combination of gut contents and stable isotopes analysis. Gut content observations indicate that P. oceanica dead leaves are an important part of the ingested food for the three species, although their tissues are constituted of only a small to medium fraction of P. oceanica carbon. Our results also underlined the potential role of these species in the degradation of P. oceanica litter by mechanically fragmenting the litter and by assimilating a small to medium fraction of carbon. Moreover, we showed that there were considerable inter- and intra-specific differences in diet composition. Diet differed between juveniles and adults for I. balthica. Crustaceans are an important food source for adults of I. balthica, while I. hectica indicated a major contribution of algal material. C. prismatica showed an intermediate diet. This trophic diversity is probably one of the factors allowing these species to coexist in the same biotope.     

Tourist facilities for disabled people on the French Riviera: a strategic model of the controversial plans to develop the seafront areas

Faced with a growing demand from the disabled community in Europe and encouraged by new regulations regarding people with disabilities, the French Riviera has joined an initiative which makes its seaside facilities more accessible. Adapted amenities are consequently currently available on the French Riviera. A survey carried out of 20 seaside tourism professionals and representatives of local institutions aimed to understand the underpinning strategies of these developments, which are very heterogeneous as regards their size, their localization, and their level of service. On the whole, it seems that on the French Riviera the services offered to disabled tourists are the product of a mixture of willingness and obligation by the regulations. Disabled people are not yet considered as real clients but as a separate population, not to be mixed with the able-bodied holiday clientele.     

Beyond Substantial Equivalence: Ethical Equivalence

The concept of substantial equivalence,introduced for the risk assessment of geneticallymodified (GM) food, is a reducing concept because itignores the context in which these products have beenproduced and brought to the consumer at the end of thefood chain. Food quality cannot be restricted to meresubstance and food acts on human beings not only atthe level of nutrition but also through theirrelationship to environment and society. To make thiscontext explicit, I will introduce an ``equivalencescale' for the evaluation of food chains (GM or notGM). By contrast with substantial equivalence, whichinvolves mainly quantitative, analytical methods ofevaluation, ``qualitative equivalence' refers to ``less'or non-substantial factors that require new methodsof evaluation based on qualitative principles.``Ethical equivalence' refers to factors that show themoral value contained in food products. To analyze thedifferent levels at which ethics is needed in foodchains, I will use the French principles: ``Liberty,Equality, Fraternity,' or freedom, equality,solidarity, and add a fourth principle:sustainability. Sustainability, solidarity, andfreedom can be applied to the evaluation ofenvironmental, socio-economic, and socio-culturalethical equivalence, respectively. Equality refers tojustice and should operate so as to guarantee thatsustainability, solidarity, and freedom are satisfied.I suggest that ethics can provide a basis for arenewal of the food chain concept. Besides QualityAssurance, it is now essential to develop an ``EthicalAssurance' and this equivalence scale could provide abasis to set up ``Ethical Assurance Standards' (EAS)for food chains.     

Metallothionein induction, antioxidative responses, glycogen and growth changes in Tubifex tubifex (Oligochaete) exposed to the fungicide, fenhexamid

Laboratory studies were conducted to determine the effects of different concentrations of fenhexamid (0.1, 1, and 10 mg L(-1)) on growth, oxidative stress, protein, glycogen, and metallothionein (MT) contents in Tubifex tubifex after an exposure of 2, 4, and 7 days. In addition, residues of the fungicide were followed in water and in the worms. In water, fenhexamid concentration decreased slowly (maximum -2 +/- 0.03% after 2 days for 1 mg L(-1)). In the worms, it increased after 4 days and decreased thereafter, confirming that the worms were exposed to the fungicide and not to a degradation product. LC50 values were between 95.22 +/- 5.36 and 32.11 +/- 1.8 mg L(-1) depending on exposure time. Exposure to fenhexamid had a negative effect on T. tubifex growth (maximum effect -12.2 +/- 0.8% after 7 days with 10 mg L(-1)) demonstrating the toxic effect of the pesticide. This growth rate decrease was accompanied by a reduction in protein and glycogen contents. The activity of catalase (CAT), and glutathione reductase (GR) increased in response to the fungicide demonstrating an oxidative stress in the worms. In contrast glutathion-S-transferase activity (GST) decreased. Exposure to fenhexamid also induced synthesis of MT (maximum +78 +/- 8% after 2 days for 10 mg L(-1)). The specificity of MT concentration increase in response to metals is discussed.     

Leaching of glyphosate and AMPA under two soil management practices in Burgundy vineyards (Vosne-Romanée, 21-France)

Some drinking water reservoirs under the vineyards of Burgundy are contaminated with herbicides. Thus the effectiveness of alternative soil management practices, such as grass cover, for reducing the leaching of glyphosate and its metabolite, AMPA, through soils was studied. The leaching of both molecules was studied in structured soil columns under outdoor conditions for 1 year. The soil was managed under two vineyard soil practices: a chemically treated bare calcosol, and a vegetated calcosol. After 680 mm of rainfall, the vegetated calcosol leachates contained lower amounts of glyphosate and AMPA (0.02% and 0.03%, respectively) than the bare calcosol leachates (0.06% and 0.15%, respectively). No glyphosate and only low amounts of AMPA (<0.01%) were extracted from the soil. Glyphosate, and to a greater extent, AMPA, leach through the soils; thus, both molecules may be potential contaminants of groundwater. However, the alternative soil management practice of grass cover could reduce groundwater contamination by the pesticide.     

Past, current and future fire frequency in the Canadian boreal forest: implications for sustainable forest management

Over the past decades, there has been an increasing interest in the development of forest management approaches that are based on an understanding of historical natural disturbance dynamics. The rationale for such an approach is that management to favor landscape compositions and stand structures similar to those of natural ecosystems should also maintain biological diversity and essential ecological functions. In fire-dominated landscapes, this approach is possible only if current and future fire frequencies are sufficiently low, comparing to pre-industrial fire frequency, that we can substitute fire by forest management. We address this question by comparing current and future fire frequency to historical reconstruction of fire frequency from studies realized in the Canadian boreal forest. Current and simulated future fire frequencies using 2 and 3 x CO2 scenarios are lower than the historical fire frequency for many sites, suggesting that forest management could potentially be used to recreate the forest age structure of fire-controlled pre-industrial landscapes. There are however, important limitations to the current even-age management.     

Sulphonated aromatic pollutants

Many synthetic sulphonated aromatic compounds are used as starting material to produce dyes and pigments, or are released as by-products in the effluents of the textile and dye industry. A large number of these chemicals are poorly biodegradable and cannot be eliminated by classical wastewater treatment plants. To limit the impact of these pollutants on the environment, new processes, based on the use of higher plants (constructed wetlands or hydroponic systems), are under development. Detergents and surfactants are essential for both industrial and domestic applications, the most important family being the alkylbenzene sulphonates. Originally, the alkyl side chains were branched and thus recalcitrant to biodegradation. Therefore, they have been replaced by linear alkylbenzene sulphonates. Although more acceptable, present formulations still have adverse environmental and toxic effects. In this context, phytoremediation appears to be a promising approach to remove these compounds from contaminated soils and waters.     

Diuron mobility through vineyard soils contaminated with copper

The herbicide diuron is frequently applied to vineyard soils in Burgundy, along with repeated treatments with Bordeaux mixture (a blend of copper sulfate and calcium hydroxide) that result in elevated copper concentrations. Cu could in principle affect the fate and transport of diuron or its metabolites in the soil either directly by complexation or indirectly by altering the populations or activity of microbes involved in their degradation. To assess the effect of high Cu concentrations on diuron transport, an experiment was designed with ten undisturbed columns of calcareous and acidic soils contaminated with 17--509 mg kg(-1) total Cu (field-applied). Grass was planted on three columns. Diuron was applied to the soils in early May and in-ground lysimeters were exposed to outdoor conditions until November. Less than 1.2% of the diuron applied was found in the leachates as diuron or its metabolites. Higher concentrations were found in the effluents from the grass-covered columns (0.1--0.45%) than from the bare-soil columns (0.02--0.14%), and they were correlated with increases in dissolved organic carbon. The highest amounts of herbicide were measured in acidic-soil column leachates (0.98--1.14%) due to the low clay and organic matter contents of these soils. Cu also leached more readily through the acidic soils (32.8--1042 microg) than in the calcareous soils (9.5--63.4 microg). Unlike in the leachates, the amount of diuron remaining in the soils at the end of the experiment was weakly related to the Cu concentrations in the soils.