Conséquences des pollutions atmosphériques sur l'agriculture et la forêt. Séminaire Agriculture et pollution de l’air

International audience | Organochlorinated compounds including PolyChloroBiphenyles, Dichloro-DiphenylTrichloroethan and metabolites are determinated in Stenella coeruleoalba (n = 37) stranded on the french Mediterranean coasts from 2007 till 2009. Studies are carried out on lung, muscle, kidney, liver, and blubber. The sought-after compounds are all detected to variable levels in each tissue and organ. In general, total PCBs are the most abondant, followed by total DDTs. The concentration (in ng g(-1) of lipid weight) in blubber of S. coeruleoalba, varied from 2,052 to 158,992 for PCBs and from 1,120 to 45,779 for DDTs. The ratios DDE/tDDTs are higher than 80% in almost all samples. The overall results of this work, compared to previous studies concerning the Mediterranean Sea, seems to confirm the tendency to a decrease of the contamination by organics compounds for the cetaceans in the Western Mediterranean Sea. (C) 2012 Elsevier Ltd. All rights reserved.

Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulation of Cd, Pd and Zn in the top few centimeters of the abyssal Mediterranean sea-bottom. In both cores, 206Pb/207Pb profiles confirm this anthropogenic impact with less radiogenic imprints toward surface sediments. The similarity between excess 210Pb accumulated in the top core and the 210Pb flux suggests that top core metal inventories reasonably reflect long-term atmospheric deposition to the open Mediterranean. Pb inventory in the western core for the past 100 years represents 20-30% of sediment coastal inventories, suggesting that long-term atmospheric deposition determined from coastal areas has to be used cautiously for mass balance calculations in the open Mediterranean. In the deeper section of both cores, Al normalized trace metal profiles suggest diagenetic remobilization of Fe, Mn, Cu and, to a lesser extent, Pb that likely corresponds to sapropel event Si

The transport mechanism of contaminated groundwater has been a problematic issue for many decades, mainly due to the bad impact of the contaminants on the quality of the groundwater system. In this paper, the exact solution of two-dimensional advection-dispersion equation (ADE) is derived for a semi-infinite porous media with spatially dependent initial and uniform/flux boundary conditions. The flow velocity is considered temporally dependent in homogeneous media however, both spatially and temporally dependent is considered in heterogeneous porous media. First-order degradation term is taken into account to obtain a solution using Laplace Transformation Technique (LTT) for both the medium. The solute concentration distribution and breakthrough are depicted graphically. The effect of different transport parameters is studied through proposed analytical investigation. Advection-dispersion theory of contaminant mass transport in porous media is employed. Numerical solution is also obtained using Crank Nicholson method and compared with analytical result. Furthermore, accuracy of the result is discussed with root mean square error (RMSE) for both the medium. This study has developed a transport and prediction 2-D model that allows the early remediation and removal of possible pollutant in both the porous structures. The result may also be used as a preliminary predictive tool for groundwater resource and management.

Much has happened in the pollution field since 1982 when the first edition of this work was written. This edition includes new subject areas such as radioactive pollution and chemistry and pollution of the stratosphere.

International audience | Pesticide contamination is often cited as a key factor in the global decline of farmland birds. However, the majority of studies on pesticide exposure in non-target fauna are not representative of what happens in nature because they are limited to artificial conditions. The aim of this study was to define and compare, for the first time, pesticide contamination in grey partridges (Perdix perdix) from two different contexts, i.e., captivity vs. the wild. Blood samples taken from 35 captive and 54 wild partridges in 2021-2022 were analysed for 94 pesticides most commonly used in French agriculture. Captive partridges had 29 molecules detected in their blood (12 herbicides, 14 fungicides, and three insecticides) compared to wild partridges, which had 50 molecules (13 herbicides, 23 fungicides, and 14 insecticides). Of these pesticide compounds found in individuals, 26 were banned. Captive partridges had significantly fewer pesticide molecules than wild partridges, with one to 14 pesticides per captive individual and 8 to 20 pesticides per wild individual. Nineteen molecules were common to both groups, with concentrations up to three times higher in wild partridges than in captive partridges. Our results thus show multiple exposures for most of our individuals, especially in wild partridges, which can lead to cocktail effects, which are never considered. Furthermore, the difference in contamination between the wild and captive partridges reflects the multiple routes of contamination in nature, in particular, due to the use of a wide range of habitats by wild partridges.

International audience | Plant protection products (PPP) are extensively used to protect plants against harmful organisms, but they also have unintended effects on non-target organisms, especially terrestrial invertebrates. The impact of PPP on ecosystem functions provided by these non-target invertebrates remains, however, unclear. The objectives of this article were to review PPP impacts on the ecosystem functions provided by pollinators, predators and parasitoids, and soil organisms, and to identify the factors that aggravate or mitigate PPP effects. The literature highlights that PPP alter several ecosystem functions: provision and maintenance of biodiversity, pollination, biotic interactions and habitat completeness in terrestrial ecosystems, and organic matter and soil structure dynamics. However, there are still a few studies dealing with ecosystem functions, with sometimes contradictory results, and consequences on agricultural provisioning services remain unclear. The model organisms used to assess PPP ecotoxicological effects are still limited, and should be expanded to better cover the wide functional diversity of terrestrial invertebrates. Data are lacking on PPP sublethal, transgenerational, and “cocktail” effects, and on their multitrophic consequences. In empirical assessments, studies on PPP unintended effects should consider agricultural-pedoclimatic contexts because they influence the responses of non-target organisms and associated ecosystem functions to PPP. Modeling might be a promising way to account for the complex interactions among PPP mixtures, biodiversity, and ecosystem functioning.

International audience | Abstract Fifty million cubic meters of marine sediments are dredged each year in France in order to maintain harbor activities and sustain the economy of littoral territories. Because of anthropogenic activities in and around harbors, sediments can contain significant amounts of chemical and organic pollutants whose behavior during dredging must be addressed in order to avoid releasing risks for humans and the environment. French regulations come to govern the management of dredged sediments, considering them “safe” and possible to be dumped at sea or “contaminated” and needed to be treated on land as waste. In recent years, new constraints have been pushed toward the management of land. This management is, however, challenging as few channels are proposed to reuse marine sediments, and elimination appears to be economically and environmentally unsustainable. This study provides an overview of the technical and regulatory aspects related to dredged marine sediment management in France and aims to identify and discuss the limits of their valorization. Dredged sediments are mainly composed of particles with heterogeneous grain size, some being known for many applications such as building materials and growing media. However, several reasons have been put forward to explain why these particles are not reused when extracted from dredged sediments. Several technical, socio-economic, and regulatory obstacles explain the low demand for dredged sediments. This demand can be stimulated by government incentives and a good regulatory framework. National regulations could help streamline their reuse by removing their “waste” status and creating a regulated market for dredged sediment.

International audience | This review investigates the impact of salinity on the fate of the active compounds of pesticides in a cultivated environment. Due to the over-exploitation of water resources and intensification of agriculture, salinity outbreaks are being observed more often in cultivated fields under pesticide treatments. Nevertheless, there is a poor understanding of the incidence of varying water salt loads on the behavior of pesticides’ active ingredients in soil and water bodies. The present review established that water salinity can affect the diffusion of pesticides’ active ingredients through numerous processes. Firstly, by increasing the vapor pressure and decreasing the solubility of the compounds, which is known as the salting-out effect, salinity can change the colligative properties of water towards molecules and the modification of exchange capacity and sorption onto the chemicals. It has also been established that the osmotic stress induced by salinity could inhibit the biodegradation process by reducing the activity of sensitive microorganisms. Moreover, soil properties like dissolved organic matter, organic carbon,clay content, and soil texture control the fate and availability of chemicals in different processes of persistence in water and soil matrix. In the same line, salinity promotes the formation of different complexes, such as between humic acid and the studied active compounds. Furthermore, salinity can modify the water flux due to soil clogging because of the coagulation and dispersion of clay particle cycles, especially when the change in salinity ranges is severe.

International audience | Human urine concentrates 88% of the nitrogen and 50% of the phosphorus excreted by humans, making it a potential alternativecrop fertilizer. However, knowledge gaps remain on the fate of nitrogen in situations favouring NH3 volatilization and on theavailability of P from urine in soils. This study aimed at identifying the fate of nitrogen and phosphorus supplied by human urinefrom source separation toilets in a calcareous soil. To this end, a spinach crop was fertilized with 2 different doses of human urine and compared with a synthetic fertilizer treatment and an unfertilized control. The experiment was conducted in 4 soil tanks (50-cm depth) in greenhouse condi-tions, according to a randomized block scheme. We monitored soil mineral nitrogen over time and simulated nitrogen volatiliza-tion using Hydrus-1D and Visual Minteq softwares. We also monitored soil phosphorus pools, carbon, nitrogen and phosphorus(CNP) in microbial biomass, soil pH and electrical conductivity. Only an excessive input of urine affected soil pH (decreasing itby 0.2 units) and soil conductivity (increasing it by 183%). The phosphorus supplied was either taken up by the crop or remainedmostly in the available P pool, as demonstrated by a net increase of the resin and bicarbonate extractable P. Ammonium seemedto be nitrified within about 10 days after application. However, both Visual Minteq and Hydrus models estimated that more than50% of the nitrogen supplied was lost by ammonia volatilization. Overall, our results indicate that direct application of urine to acalcareous soil provides available nutrients for plant growth, but that heavy losses of volatilized nitrogen are to be expected. Ourresults also question whether long-term application could affect soil pH and salinity.