Background Chlorobenzoic acids (CBA) are intermediate products of the aerobic microbial degradation of PCB and several pesticides. This study explores the feasibility of using basket willows, Salix viminalis, to remove 4-CBA from polluted sites, which also might stimulate PCB degradation. Methods The removal of 4-CBA by willow trees was investigated with intact, septic willow trees growing in hydroponic solution and with sterile cell suspensions at concentrations of 5 mg/L and 50 mg/L 4-CBA. Nutrient solutions with different levels of ammonium and nitrate were prepared to achieve different pH levels. The concentration of 4-CBA was tracked over time and quantified by HPLC. Results and discussion At the low level of 4-CBA (5 mg/L), willows removed 70% (pH 4.2) to 90% (pH 6.8), while 48% (pH 4.2) to 52% (pH 6.8) of the water was transpired. At the high 4-CBA level (50 mg/L), the pH varied between 4.4 and 4.6, and 10% to 30% of 4-CBA was removed, but only 5% to 9% of the water. In sterile cell suspensions, removal of 4-CBA by fresh biomass was much higher than removal by dead biomass. Conclusions The results indicate that 4-CBA is toxic to willow trees at 50 mg/L. The removal of 4-CBA from solution is by both passive processes (uptake with water, sorption to plant tissue) and metabolic processes of the plants. Recommendations and outlook Plants, such as willow trees, might assist in the degradation of PCB and their degradation products CBA.

With the aim of developing new uses of sewage sludge, a byproduct of municipal wastewater treatment plants, in the present work the calcination at 900° C of this waste with or without CaCO3 added was performed; the sludge was obtained from a local municipal wastewater treatment plant. The purpose was to study the ability of the CaCO3 to capture SO 2 during the incineration. The resulting ashes were reactivated at different experimental conditions to obtain desulfurant sorbents to be used in a further desulfurization process at low tempreature. The humidity, total solids and fixed and volatile solids were determined in the sludge with and without CaCO3 added. The elementary analysis of the dry sludge and of the calcinated was obtained. Results show that the C percentage highly decreases in the incineration due to the release of the volatile carbon compounds. The sulphur percentage increases principally due to the release of the volatile matter. The resulting ashes with or without CaCO3 added were studied by Thermogravimetry. T.G. curves show that not all the CaCO3 was calcinated mainly when the amout of CaCO3 added was high. The specific surface area of the dry sludge, of the ashes and of the sorbents prepared by reacitivation of the ashes was also determined | We are thankful to MICINN for financial support of this work under Porject MAT 2009-10727

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.

There is currently a lack of ecotoxicity tests adapted to earthworm species of higher ecological relevance and whose endpoints could be directly related to their ecological role in the soil. We propose a new and relatively simple ecotoxicity test based on the estimation of cast production (CP) by Lumbricus terrestris under laboratory conditions. CP was found to be linearly correlated to earthworm biomass and to be greatly influenced by soil water content. Azinphos-methyl had no effect on CP at all the concentrations tested. Significant decreases were observed at the normal application rate for other pesticides with (imidacloprid, carbaryl, methomyl) or without (ethyl-parathion and chlorpyrifos-ethyl) a clear concentration–effect response. For the highest concentration tested, reduction in CP varied between 35 and 67%. CP is straightforward and rapidly measured and ecologically meaningful. We thus believe it to be of great use as an endpoint in ecotoxicity testing.

International audience | Can the existence and the density of particular plant species give several informations about the degree of soil pollution? After having chosen different sites for this survey, the identification of collected plant species and the soil characteristics of collection sites were compared and some correlations were established. Data on growth of collected plants indicated the existence of two ecotypes of Thlaspi caerulescens. It has been shown the preference of one of the ecotypes for the metal-contaminated soils. | La présence et l'abondance de certaines espèces végétales peuvent-elles donner des informations sur l'état de pollution d'un sol ? Après avoir choisi des sites d'étude, y avoir caractérisé des peuplements végétaux et la pollution du sol pour établir des corrélations, une mise en culture des plantes a permis de mettre en évidence deux écotypes de Thlaspi caerulescens et une préférence de l'un des deux pour les sols pollués. Mots-clés Pollutions minières, métaux lourds, bioindicateur, Thlaspi caerulescens, phytostabilisation.

Increased atmospheric CO2 concentrations are causing greater dissolution of CO2 into seawater, and are ultimately responsible for today's ongoing ocean acidification. We manipulated seawater acidity by addition of HCl and by increasing CO2 concentration and observed that two coastal harpacticoid copepods, Amphiascoides atopus and Schizopera knabeni were both more sensitive to increased acidity when generated by CO2. The present study indicates that copepods living in environments more prone to hypercapnia, such as mudflats where S. knabeni lives, may be less sensitive to future acidification. Ocean acidification is also expected to alter the toxicity of waterborne metals by influencing their speciation in seawater. CO2 enrichment did not affect the free-ion concentration of Cd but did increase the free-ion concentration of Cu. Antagonistic toxicities were observed between CO2 with Cd, Cu and Cu free-ion in A. atopus. This interaction could be due to a competition for H+ and metals for binding sites.

An increasing amount of scientific information is available on water pollution and its effect. Water pollution management for pollution control seldom considers the scientific information. The main objective of this paper is to review the water pollution management in Bangkok and link the entire process to the cause and effects of water pollution. Existing approaches for water pollution control primarily focuses on enforcing various standards. Respective local authorities in Bangkok have also set their own surface water quality requirement. However, the entire management approach requires further analysis in line with the present situation. This paper attempts to review the entire management approach and suggests reduction strategies, control measures/treatment systems and some preferred solutions to the water pollution management. It also covers other important measures for control. The conclusion proposes some policy recommendations on reducing pollution through effect management approach.

We present here the effects of ambient ozone (O3)-induced decline in carbon availability, accelerated foliar senescence, and a decrease in aboveground biomass accumulation in the Aleppo pine (Pinus halepensis Mill.). Aleppo pine seedlings were continuously exposed in open-top chambers for 39 months to three different types of O3 treatments, which are as follows: charcoal-filtered air, nonfiltered air (NFA), and nonfiltered air supplemented with 40 ppb O3 (NFA+). Stable carbon isotope discrimination (Δ) and derived time-integrated ci/ca ratios were reduced after an accumulated ozone exposure over a threshold of 40 ppb (AOT40) value from April to September of around 20,000 ppb·h. An AOT40 of above 67,000 ppb·h induced reductions in ribulose-1, 5-biphosphate carboxylase/oxygenase activity, aboveground C and needle N and K concentrations, the C/N ratio, Ca concentrations in twigs under 3 mm, and the aerial biomass, as well as increases in needle P concentrations and phosphoenolpyruvate carboxylase (PEPC) activity and the N and K concentrations in twigs under 3 mm. Macronutrients losses, the limitations placed on carbon uptake, and increases in catabolic processes may be the causes of carbon gain diminution in leaves which was reflected as a reduction in aboveground biomass at tree level. Stimulation of PEPC activity, the consequent decreased Δ, and compensation processes in nutrient distribution may increase O3 tolerance and might be interpreted as part of Aleppo pine acclimation response to O3.

Seasonality of biomarker baseline levels were studied in polar cod (Boreogadus saida), caught in Kongsfjorden, Svalbard, in April, July, September and December, 2006-2007. Physiological parameters (condition factor, gonado- and hepato-somatic indexes, energy reserves, potential metabolic activity and antifreeze activity) in polar cod were used to interpret the seasonality of potential biomarkers. The highest levels of ethoxyresorufin-O-deethylase (EROD) activity occurred concomitantly with the highest potential metabolic activity in July due to e.g. intense feeding. During pre-spawning, EROD showed significant inhibition and gender differences. Hence, its potential use in environmental monitoring should imply gender differentiation at least during this period. Glutathione S-transferase and catalase activities were stable from April to September, but changed in December suggesting a link to low biological activity. Knowledge of the biomarker baseline levels and their seasonal trends in polar cod is essential for a trustworthy interpretation of forthcoming toxicity data and environmental monitoring in the Arctic.