Drugs of abuse and their metabolites in the Ebro River basin: occurrence in sewage and surface water, sewage treatment plants removal efficiency, and collective drug usage estimation.

Drugs of abuse and their metabolites have been recently recognized as environmental emerging organic contaminants. Assessment of their concentration in different environmental compartments is essential to evaluate their potential ecotoxicological effects. It also constitutes an indirect tool to estimate drug abuse by the population at the community level. The present work reports for the first time the occurrence of drugs of abuse and metabolites residues along the Ebro River basin (NE Spain) and also evaluates the contribution of sewage treatment plants (STPs) effluents to the presence of these chemicals in natural surface waters. Concentrations measured in influent sewage waters were used to back calculate drug usage at the community level in the main urban areas of the investigated river basin. The most ubiquitous and abundant compounds in the studied aqueous matrices were cocaine, benzoylecgonine, ephedrine and ecstasy. Lysergic compounds, heroin, its metabolite 6-monoacetyl morphine, and Delta(9)-tetradhydrocannabinol were the substances less frequently detected. Overall, total levels of the studied illicit drugs and metabolites observed in surface water (in the low ng/L range) were one and two orders of magnitude lower than those determined in effluent (in the ng/L range) and influent sewage water (microg/L range), respectively. The investigated STPs showed overall removal efficiencies between 45 and 95%. Some compounds, such as cocaine and amphetamine, were very efficiently eliminated (>90%) whereas others, such as ecstasy, methamphetamine, nor-LSD, and THC-COOH where occasionally not eliminated at all. Drug consumption estimates pointed out cocaine as the most abused drug, followed by cannabis, amphetamine, heroin, ecstasy and methamphetamine, which slightly differs from national official estimates (cannabis, followed by cocaine, ecstasy, amphetamine and heroin). Extrapolation of the consumption data obtained for the studied area to Spain points out a total annual consumption of drugs of abuse of the order of 36 tonnes, which would translate into 1100million Euros in the black market.

Analysis of 17 polar to semi-polar pesticides in the Ebro river delta during the main growing season of rice by automated on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry.

This work describes the optimization of a fully automated method based on on-line solid-phase extraction-liquid chromatography-electrospray-tandem mass spectrometry (SPE-LC-ESI-MS/MS) for the simultaneous determination of 17 medium to polar pesticides in water. The list of target analytes included organophosphates, triazines, phenylureas, anilides, chloroacetanilides, acidic herbicides and thiocarbamates. Detection limits achieved were below 5 ng/L for all compounds except metolachlor (12 ng/L), alachlor (17 ng/L), malathion (36 ng/L) and fenitrothion (50 ng/L). The method developed was used to investigate the occurrence of the target pesticides in a total of 52 water samples collected monthly (from May to August 2005) at 14 selected locations in the rice cultivation area of the Ebro river delta. The study showed high levels, in the microg/L range, of bentazone, MCPA, propanil, molinate and atrazine, in basically all the samples investigated. The remaining pesticides were present at lower levels (<0.1 microg/L) or only detected sporadically (e.g. fenitrothion and malathion). The sampling campaign performed in July showed comparatively higher levels than the other three campaigns.

Determination of antimicrobials in sludge from infiltration basins at two artificial recharge plants by pressurized liquid extraction-liquid chromatography-tandem mass spectrometry.

This work describes the optimization of a multi-residue analytical approach for the simultaneous determination of 11 antimicrobials (9 sulphonamides and 2 penicillins) in sludge from infiltration basins. The method is based on pressurized liquid extraction (PLE) followed by solid-phase extraction (SPE) for pre-concentration and purification, and analysis by liquid chromatography-tandem mass spectrometry using electrospray in the positive ionization mode (LC-(ESI+)-MS/MS). Limits of detections (LODs) between 1 pg/g and 0.2 ng/g and limits of quantifications (LOQs) between 5 pg/g and 0.6 ng/g were achieved. Good recovery values (57.6-104%) were obtained for sulfamethazine, sulfapyridine, sulfadiazine and sulfamethoxypyridazine, while medium recovery values (14-47%) were afforded for sulfadimethoxine, sulfathiazole and sulfamethoxazole. However, only a poor recovery (<1%) could be possible for both penicillins and two sulphonamides, namely nafcillin, dicloxacillin, sulfisoxazole and sulfamethizole. These low recoveries were attributed to the presence of ionic suppression effects (even after thorough extraction and purification) rather than to an inefficient extraction. The method developed was applied to the analysis of sludge samples from the infiltration basins of two artificial recharge plants located in Sweden and Denmark. All target compounds were found to be present in at least one sample. Sulfadimethoxine, nafcillin and dicloxacillin were detected in all the samples analysed.

MODELKEY. Models for assessing and forecasting the impact of environmental key pollutants on freshwater and marine ecosystems and biodiversity.

BACKGROUND: Triggered by the requirement of Water Framework Directive for a good ecological status for European river systems till 2015 and by still existing lacks in tools for cause identification of insufficient ecological status MODELKEY (http:// www.modelkey.org), an Integrated Project with 26 partners from 14 European countries, was started in 2005. MODELKEY is the acronym for 'Models for assessing and forecasting the impact of environmental key pollutants on freshwater and marine ecosystems and biodiversity'. The project is funded by the European Commission within the Sixth Framework Programme. OBJECTIVES: MODELKEY comprises a multidisciplinary approach aiming at developing interlinked tools for an enhanced understanding of cause-effect-relationships between insufficient ecological status and environmental pollution as causative factor and for the assessment and forecasting of the risks of key pollutants on fresh water and marine ecosystems at a river basin and adjacent marine environment scale. New modelling tools for risk assessment including generic exposure assessment models, mechanistic models of toxic effects in simplified food chains, integrated diagnostic effect models based on community patterns, predictive component effect models applying artificial neural networks and GIS-based analysis of integrated risk indexes will be developed and linked to a user-friendly decision support system for the prioritisation of risks, contamination sources and contaminated sites. APPROACH: Modelling will be closely interlinked with extensive laboratory and field investigations. Early warning strategies on the basis of sub-lethal effects in vitro and in vivo are provided and combined with fractionation and analytical tools for effect-directed analysis of key toxicants. Integrated assessment of exposure and effects on biofilms, invertebrate and fish communities linking chemical analysis in water, sediment and biota with in vitro, in vivo and community level effect analysis is designed to provide data and conceptual understanding for risk arising from key toxicants in aquatic ecosystems and will be used for verification of various modelling approaches. CONCLUSION AND PERSPECTIVE: The developed tools will be verified in case studies representing European key areas including Mediterranean, Western and Central European river basins. An end-user-directed decision support system will be provided for cost-effective tool selection and appropriate risk and site prioritisation.