In Guadeloupe, the use between 1972 and 1993 of chlordecone, an organochlorine insecticide, has permanently contaminated the island's soil, thus contaminating the food chain at its very beginning. There is today a strong societal requirement for an improved mapping of the contaminated zones. Given the extent of the areas to be covered, carrying out soil tests on each plot of the territory would be a long and expensive process. In this article, we explore a method of demarcating polluted areas. The approach adopted consists in carrying out, using surface water analyses, a hydrological delimitation that makes it possible to distinguish contaminated watersheds from uncontaminated ones. The selection of sampling points was based on the spatial analysis of the actual and potential contamination data existing at the beginning of the study. The approach was validated by soil analyses, after having compared the contamination data of the watersheds with the soil contamination data of the plots within them. The study thus made it possible to highlight new contaminated areas and also those at risk of contamination and to identify the plots to be targeted as a priority during future analysis campaigns by State services.

Chlordecone was applied between 1972 and 1993 in banana fields of the French West Indies. This resulted in long-term pollution of soils and contamination of waters, aquatic biota, and crops. To assess pollution level and duration according to soil type, WISORCH, a leaching model based on first-order desorption kinetics, was developed and run. Its input parameters are soil organic carbon content (SOC) and SOC/water partitioning coefficient (Koc). It accounts for current chlordecone soil contents and drainage water concentrations. The model was valid for andosol, which indicates that neither physicochemical nor microbial degradation occurred. Dilution by previous deep tillages makes soil scrapping unrealistic.Lixiviation appeared the main way to reduce pollution. Besides the SOC and rainfall increases, Koc increased from nitisol to ferralsol and then andosol while lixiviation efficiency decreased. Consequently, pollution is bound to last for several decades for nitisol, centuries for ferralsol, and half a millennium for andosol.

Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroResp™ technique, in a pollution-induced community tolerance approach. The results show that MicroResp™ can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroResp™ was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river. A modified MicroResp™ technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community

Morocco is the first country producer of phosphate in the world with a real potential of contamination of the environment and individuals there living by fluorine either by phosphate deposits (hydrotelluric fluorosis) and phosphate manufacturing plants (industrial fluorosis). This survey was achieved on 86 dromedaries in a region of the Sahara (Boujdour and Laâyoune) characterized by the presence of phosphate. In addition, blood, soil, water and plant samples were collected for the dosage of fluorine that has been achieved by potentiometric method. The mean fluorine content was below 0.47 ppm, 513 ppm and 4.8 ppm in water, soil and plants respectively. The provinces of Boujdour and Laâyoune are unscathed zones opposite the sources of fluorine contamination, as water, vegetation and soil. The mean plasma fluorine concentration was below 0.06 ppm, thus, the camels of these regions seem therefore also free of fluorine chronic intoxication. However the increased values of fluorine levels in the soil, vegetables, and the plasma of camels in the region of Boujdour can let suppose that this area is close to a source of fluorine contamination. Indeed, the province of Boujdour is located unless 200 km of Boukraa where is situated a processing plant of phosphates. Thus, according orientation and the strength of the present dominant winds in the region of Boujdour, we can give out the hypothesis that by winds are brought in the region of Boujdour of the fluorine particles coming from the region of Boukraa. These winds carrying particles of fluorine eliminated by the factory and also by the extraction of soil particles by erosion. This hypothesis can be verified by a survey establishing a gradient of pollution by fluorine cleared by the deposit or the processing plant of the phosphates considering the direction and the strength of the dominant winds in these regions. (Résumé d'auteur)

Since its independence in 1991, Kazakhstan is in a state of "ecological crises", due to the specific place for nuclear test by soviet government for long time, and to the development of irrigation for field cottons linked with decreasing Aral Sea level. In addition the manufacturing of metals and the minerals had some impact on environmental contamination. In the South of Kazakhstan, eight farms were sampled close to probable pollution sources. Samples of camel milk, fodder and water were collected in each farm and analyzed for copper, iron, manganese, zinc, arsenic and lead. The mean content in fodder of Cu, Fe, Mn, Zn, As and Pb was 10.40 ± 2.93, 793.69 ± 630.48, 62.38 ± 20.67, 32.95 ± 27.15, 1.03 ± 0.49 and 4.28 ± 9.60 ppm respectively. In camel milk mean content of these heavy metals was respectively of 0.07 ± 0.04, 1.48 ± 0.53, 0.08 ± 0.03, 5.16 ± 2.17, <0.1, and 0.025 ± 0.02 ppm respectively. No heavy metals were detected in samples of water with the analytical methods used. The relationships between heavy metals in water, forages and milk were not clear. Some information's are lacking. We need to extend sampling at more areas where camels, cows, goat and sheep farms are closed to pollution areas, and analyzed other heavy metals suspected in pollution process.

Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroRes (TM) technique, in a pollution-induced community tolerance approach. The results show that MicroRes (TM) can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroRes (TM) was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river. A modified MicroRes (TM) technique as a tool for measuring induced tolerance to heavy metals of a microbial biofilm community.