Search

This research presents the occurrence and fate of 121 contaminants of emerging concern (CECs) in an urban aquifer polluted by river recharge through a data-base modelling. Afterwards, risk quotients (RQs) are computed to determine the risk posed by CECs to human health. To this end, groundwater and river water samples were collected in four campaigns conducted from February to May 2021. Results show that 46 CECs are ubiquitous in groundwater and their concentrations vary several orders of magnitude, ranging from below the limit of quantification to 44.5·103 ng/L for iopamidol. Transformation products (TPs) are usually detected at lower concentrations than those of the parent substances but there are some exceptions (i.e., fipronil sulphide, fipronil sulfone and O-desmethylvenlafaxine). River concentrations are higher than those detected in groundwater for some CECs, indicating the occurrence of natural attenuation processes when river water infiltrates the aquifer. A data-based advection-reaction modelling is proposed and tested for ca. 40 substances with detection frequencies higher than 90%. It provides useful quantitative information regarding the dynamic behaviour of the variables monitored, expressed in terms of characteristic length, entropy and synchronized state contribution. Finally, risk quotients (RQs) are used to assess the human health risk posed by the ubiquitous CECs in groundwater. Most CECs do not pose any risk to the different life stages considered, as the RQs evaluated are lower than 0.01. However, the pharmaceuticals valsartan and its TP valsartan acid show RQs higher than 1, indicating that these substances might be harmful to human beings., This research has been supported through the grant CEX2018-000794-S funded by MCIN/AEI/10.13039/501100011033 and the UrbanWat project (JPI-JC-2018_16) from the “Agencia Estatal de Investigación” from the Spanish Ministry of Science and Innovation.

Temporary rivers become dependent on wastewater effluent for base flows, which severely impacts river ecosystems through exposure to elevated levels of nutrients, dissolved organic matter, and organic micropollutants. However, biodegradation processes occurring in these rivers can be enhanced by wastewater bacteria/biofilms. Here, we evaluated the attenuation of pharmaceuticals and their human metabolites performing retrospective analysis of 120 compounds (drugs, their metabolites and transformation products) in mesocosm channels loaded with wastewater effluents twice a week for a period of 31 days. Eighteen human metabolites and seven biotransformation products were identified with high level of confidence. Compounds were classified into five categories. Type-A: recalcitrant drugs and metabolites (diclofenac, carbamazepine and venlafaxine); Type-B: degradable drugs forming transformation products (TPs) (atenolol, sitagliptin, and valsartan); Type-C: drugs for which no known human metabolites or TPs were detected (atorvastatin, azithromycin, citalopram, clarithromycin, diltiazem, eprosartan, fluconazole, ketoprofen, lamotrigine, lormetazepam, metformin, telmisartan, and trimethoprim); Type-D: recalcitrant drug metabolites (4-hydroxy omeprazole sulfide, erythro/threo-hydrobupropion, and zolpidem carboxylic acid); Type-E: unstable metabolites whose parent drug was not detectable (norcocaine, benzolylecgonine, and erythromycin A enol ether). Noteworthy was the valsartan acid formation from valsartan with transient formation of TP-336., This study has been financially supported by the EU through the PRIMA project (INWAT 201980E121). This work was supported by the Spanish Ministry of Science and Innovation (Project CEX2018-000794-S). The authors also acknowledge SCIEX for providing the loan instrument LC/HRMS QTOF X500R. The EU is not liable for any use that may be made of the information contained therein.

Urban wastewater inputs are a relevant pollution source to rivers, contributing a complex mixture of nutrients, organic matter and organic microcontaminants to these systems. Depending on their composition, WWTP effluents might perform either as enhancers (subsidizers) or inhibitors (stressors) of biological activities. In this study, we evaluated in which manner biofilms were affected by treated urban WWTP effluent, and how much they recovered after exposure was terminated. We used indoor artificial streams in a replicated regression design, which were operated for a total period of 56 days. During the first 33 days, artificial streams were fed with increasing concentration of treated effluents starting with non-contaminated water and ending with undiluted effluent. During the recovery phase, the artificial streams were fed with unpolluted water. Sewage effluents contained high concentrations of personal care products, pharmaceuticals, nutrients, and dissolved organic matter. Changes in community structure, biomass, and biofilm function were most pronounced in those biofilms exposed to 58% to 100% of WWTP effluent, moving from linear to quadratic or cubic response patterns. The return to initial conditions did not allow for complete biofilm recovery, but biofilms from the former medium diluted treatments were the most benefited (enhanced response), while those from the undiluted treatments showed higher stress (inhibited response). Our results indicated that the effects caused by WWTP effluent discharge on biofilm structure and function respond to the chemical pressure only in part, and that the biofilm dynamics (changes in community composition, increase in thickness) imprint particular response pathways over time. © 2019 Elsevier B.V., This study has been financially supported by the EU FP7 project GLOBAQUA [Grant Agreement No. 603629] and by the Generalitat de Catalunya [Consolidated Research Groups: 2017 SGR 01404−Water and Soil Quality Unit]. NM thanks SCIEX for generously providing the loaned instrument. Authors are grateful to Vicenç Acuña, Maria Casellas, Ferran Romero and Olatz Pereda for their support and advice during the experiment, and to Peter Eichhorn for his critical reading of the manuscript.

Degradation of solid polymers in the aquatic environment encompasses a variety of biotic and abiotic processes giving rise to heterogeneous patterns across the surface of the material, which cannot be investigated using conventional Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) that only renders an "average" picture of the sample. In that context, MALDI-TOF MS Imaging (MALDI MSI) provides a rapid and efficient tool to study 2D spatial changes occurred in the chemical composition of the polymer surface.Commercial polycaprolactone diol (average molecular weight of 1250 Da) was selected as test material because it had been previously known to be amenable to biological degradation. The test oligomer probe was incubated under aerobic and denitrifying conditions using synthetic water and denitrifying mixed liquor obtained from a wastewater treatment plant respectively. After ca. seven days of exposure the mass spectra obtained by MALDI MSI showed the occurrence of chemical modifications in the sample surface. Observed heterogeneity across the probe's surface indicated significant degradation and suggested the contribution of biotic processes. The results were investigated using different image processing tools. Major changes on the oligomer surface were observed when exposed to denitrifying conditions. © 2016., This study has been financially supported by the EU through the FP7 project GLOBAQUA (Grant agreement No 603629 ), and by the Generalitat de Catalunya (Consolidated Research Groups “2014 SGR 418—Water and Soil Quality Unit” and "2014 SGR 291—ICRA"). It reflects only the author's views. The Community is not liable for any use that may be made of the information contained therein. The authors are thankful to Dr. P. Eichhorn for his critical reading of the manuscript and the valuable comments provided and to Maria Casellas (Experimental Streams Facility, Catalan Institute for Water Research, Girona, Spain) for her technical help in the operation of the artificial stream. Appendix A

Pollutants' dynamics in rivers flowing through industrial areas is linked to the entrainment and transport of contaminants attached to solid particles. The transport of sediment is mainly associated to high discharges and flood episodes, and these events constitute one of the main factors causing fluxes of buried pollutants in rivers. We performed a field study in the lower River Cinca (Ebro basin, Northeast Spain) to quantify the mobilization and transfer of several contaminants present in the river bed sediments. We focused on contaminants previously identified (PCBs, DDXs, PBDEs, HBCDs and PFRs) to occur in the river. River bed sediment samples were collected during low flows and a subsequent sampling campaign was used to capture sediment borne contaminants during a flood event. Water samples were taken at the same locations as the static sediment samples and used to determine the suspended sediment concentrations and the contaminants content (i.e. mass of contaminant per sediment mass unit) during the event. We estimated mass fluxes for both sediment and pollutants, and determined that sediment transport followed a clockwise hysteresis. This is typically observed in high flow events after dry summer periods. With sediments there was a large mobilization of PFRs (36 kg in 48 h in one of the main tributaries) and PCBs not previously observed in the static sediment. Observed contaminant load ranges during the two-day sampling campaign were: PCB (34–152 g), DDT (12–213 g), PBDE (50–1740 g), HBCD (0–2.2 g) and PFR (2410–35,895 g). An environmental risk assessment was carried out by comparing the pollutant concentrations found in the sediments with the Canadian quality guidelines (ISQC), showing a significant noncompliance for PCBs in dynamic sediments. Our results point out to the need of a regular assessment of the downstream transfer of the sediment-borne pollutants in drainage basins historically affected by intense industrial activities and associated contamination. The authors are grateful to the reviewers, whose valuable suggestion contributed to improving the present manuscript. This work was funded by the EU through the FP7 Project GLOBAQUA (grant agreement 603629) and the Redes de Excelencia project NET-SCARCE (CTM2015-69780-REDC). Authors acknowledge the support from the Economy and Knowledge Department of the Catalan Government through Consolidated Research Groups ICRA-ENV 2017 SGR 1124 and 2017 SGR 459 Fluvial Dynamics Research Group (RIUS). Authors thank Efren Muñoz who helped during the sampling campaign and provided turbidity data.

We used the trait composition of macroinvertebrate communities to identify the effects of pesticides and multiple stressors associated with urban land use at different sites of four rivers in Spain. Several physical and chemical stressors (high metal pollution, nutrients, elevated temperature and flow alterations) affected the urban sites. The occurrence of multiple stressors influenced aquatic assemblages at 50% of the sites. We hypothesized that the trait composition of macroinvertebrate assemblages would reflect the strategies that the assemblages used to cope with the respective environmental stressors. We used RLQ and fourth corner analysis to address the relationship between stressors and the trait composition of benthic macroinvertebrates. We found a statistically significant relationship between the trait composition and the exposure of assemblages to environmental stressors. The first RLQ dimension, which explained most of the variability, clearly separated sites according to the stressors. Urban-related stressors selected taxa that were mainly plurivoltine and fed on deposits. In contrast, pesticide impacted sites selected taxa with high levels of egg protection (better egg survival), indicating a potentially higher risk for egg mortality. Moreover, the trait diversity of assemblages at urban sites was low compared to that observed in pesticide impacted sites, suggesting the homogenization of assemblages in urban areas.

In the present work, a new method is proposed for the analysis of linear (lVMS) and cyclic methylsiloxanes (cVMS) in waters and sediments. The method is based on liquid-liquid extraction followed by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) using a triple quadrupole analyser (QqQ) working in selected reaction monitoring (SRM) mode. The instrumental parameters were optimized taking into account the interaction between different parameters and not only individual effects of variables. The method was validated yielding to convenient linearity and precision (RSD%16%), and limits of quantification in the low ng/L and ng/g orders for wastewaters and river sediments, respectively. To the author's knowledge it is the first time that GC-MS/MS is used for analyzing methylsiloxanes in waters and sediments. The method was applied to the analysis of surface water and river sediments from the Llobregat River and Riera de Rubí (Catalonia, NE of Spain) and the influents and effluents of 17 wastewater treatment plants (WWTPs). The main results of this study showed that methylsiloxanes were present in all the analyzed wastewater samples, with cVMS being found at higher concentrations. Decamethylcyclopentasiloxane (D5) was the predominant compound, the maximum concentration was 8915 ng/L in influent wastewater and treated effluents, and the median concentration was 273 ng/L. Although these samples were collected primarily for method development purposes and have limited statistical value for characterizing spatial and temporal patterns, they represent a significant contribution to dataset needed to verify exposure calculations in environmental risk assessment studies, for a significantly wide range of dimethylsiloxane analytes.

The occurrence of 73 representative pharmacologically active compounds (PhACs) was assessed in a sewage-impacted section of the Llobregat River (NE Catalonia, Spain). This Mediterranean river is characterized by flow rate fluctuations strongly influenced by seasonal rainfall. River flow variations increase the potential environmental risk posed by organic micro-pollutants as their concentrations may increase substantially under low flow conditions. Little is known about the transport behavior of emerging contaminants in surface waters once they are discharged from waste water treatment plants (WWTP) into rivers. This research aimed to study the presence and fate of emerging contaminants under different hydrological conditions by sampling two different sites along the river in different seasons. The highest levels of pharmaceuticals were determined during cold and dry periods. The impact of the flow changes on the concentration of the pharmaceuticals in the river was assessed with the relative sensitive coefficients. Due to expected dilution effects, the response of pharmaceuticals to river flow was negative. Only in a few cases, positive relationships between drug concentrations and flow were detected, suggesting an important role of other hydrological phenomena like sediment re-suspension as well as the source of pollutants. To evaluate the role of other factors influencing PhAC concentrations, a plug-flow model was applied to obtain disappearance constants "k" for a set of selected compounds. Erythromycin presented k values of -0.15 h(-1) in both sites being the compound more efficiently removed from the water column. The k values for ibuprofen, furosemide, enrofloxacin, enalapril, acetaminophen, diclofenac and Ketoprofen were between -0.04 and -0.10 h(-1) showing less disappearance than erythromycin in the water column. However, other compounds presented k values0.06, which suggested conservative behavior of these compounds in the water column. This study supports the reliability of the calculated k values for the disappearance of compounds in river waters.

Data from four Spanish basin management authorities were analysed. Chemical and biological data from four Spanish basin management authorities were analysed, focusing on three consecutive years. Aims were to i) determine the chemicals most likely responsible for the environmental toxicological risk in the four Spanish basins and ii) investigate the relationships between toxicological risk and biological status in these catchments. The toxicological risk of chemicals was evaluated using the toxic unit (TU) concept. With these data we considered if the potential risk properly reflects the risk to the community or, alternatively, if new criteria should be developed to improve risk assessment. Data study revealed inadequacies in processing and monitoring that should be improved (e.g., site coincidence for chemical and biological sampling). Analysis of the chemical data revealed high potential toxicological risk in the majority of sampling points, to which metals were the main contributors to this risk. However, clear relationships between biological quality and chemical risk were found only in one river. Further investigation of metal toxicity may be necessary, and future analyses are necessary to accurately estimate the risk to the environment., The present work was funded by the Spanish Ministry of Economics and Competitiveness through the Consolider-Ingenio 2010 Program (project Scarce CSD2009-00065). The authors would like to acknowledge the Confederacion Hidrografica del Ebro (C. Duran and V. Sanchez-Tello), Confederacion Hidrografica del Guadalquivir (V. Cifuentes), Agenda Andaluza del Agua, Agenda Catalana de l'Aigua (A Munne, L Tirapu) and Confederacion Hidrografica del Jucar (MA Pinon) which kindly provided the monitoring data. Nuria De Castro-Catala holds a predoctoral grant from the University of Barcelona. We would like to thank two anonymous reviewers for their suggestions which have improved this manuscript.

Ecotoxicological risk assessment of chemical pollution in four Iberian river basins (Llobregat, Ebro, Júcar and Guadalquivir) was performed. The data set included more than 200 emerging and priority compounds measured at 77 sampling sites along four river basins studied. The toxic units (TU) approach was used to assess the risk of individual compounds and the concentration addition model (CA) to assess the site specific risk. Link between chemical pollution and aquatic macroinvertebrate communities in situ was examined by using four biological indexes; SPEAR ("Species at Risk Index") as the indicator of decline of sensitive species in relation to general organic (SPEARorganic) and pesticides (SPEARpesticides) pollution; and Shannon and Margalef biodiversity indexes. The results of the study suggested that organic chemicals posed the risk of acute effects at 42% of the sampling sites and the risk of chronic effects at all the sites. Metals posed the acute risk at 44% of the sites. The main drivers of the risk were mainly pesticides and metals. However, several emerging contaminants (e.g. the antidepressant drug sertraline and the disinfectant triclosan) were contributing to the chronic effects risk. When risk associated with metals and organic chemicals was compared, the latter dominated in 2010, mainly due to the presence of highly toxic pesticides, while metals did in 2011. Compounds that are not regulated on the European level were posing the risk of chronic effects at 23% of the sites. The decline of sensitive macroinvertebrate taxa expressed in terms of SPEAR index was correlated with the increase of toxic stress related to organic compounds Biodiversity indexes were negatively correlated with the metals and the urban land use type in the catchment This study has been financially supported by the EU through the FP7 project GLOBAQUA (Grant Agreement No. 603629), by the Spanish Ministry of Economy and Competitiveness [project Consolider-Ingenio 2010 SCARCE CSD2009-00065] and by the Generalitat de Catalunya (Consolidated Research Groups: 2014 SGR 418 – Water and Soil Quality Unit and 2014 SGR 291-ICRA)

Mediterranean rivers are characterized by a high flow variability, which is strongly influenced by the seasonal rainfall. When water scarcity periods occur, water flow, and dilution capacity of the river is reduced, increasing the potential environmental risk of pollutants. On the other hand, floods contribute to remobilization of pollutants from sediments. Contamination levels in Mediterranean rivers are frequently higher than in other European river basins, including pollution by pharmaceutical residues. Little attention has been paid to the transport behavior of emerging contaminants in surface waters once they are discharged from WWTP into a river. In this context, this work aimed to relate presence and fate of emerging contaminants with hydrological conditions of a typical Mediterranean River (Llobregat, NE Spain). River fresh water samples were collected twice a week over a period of 5 weeks at three sampling points. Sixty-six pharmaceutical compounds belonging to different therapeutical classes were analyzed by LC-MS/MS. Positive and negative correlations between the concentrations of the target analytes and hydrological variables like river flow and dissolved organic matter were observed pointing out the relevance of different hydrological phenomena like dilution effects or sediment re-suspension. Sensitivity calculations showed that the majority of compounds were sensitive to flow variations

Contamination of surface waters by pesticides continues to be the focus of concern for water authorities due to the growing evidence of their deleterious effects on aquatic life. In this context, the present work investigates the occurrence of 16 selected pesticides belonging to the classes of triazines, phenylureas, organophosphates, chloroacetanilides and thiocarbamates in surface waters from the Llobregat River (NE Spain) and some of its tributaries (Anoia and Rubí) and assesses their potential impact on the aquatic organisms by applying a recently developed index, the Short-term Pesticide Risk Index for the Surface Water System (PRISW-1), which takes into account the pesticides concentrations and their overall toxicity against three aquatic organisms (algae, Daphnia, and fish). Chemical analysis, performed by means of a fully automated method based on isotope dilution on-line solid phase extraction–liquid chromatography– electrospray–tandem mass spectrometry (on-line SPE–LC–ESI–MS/MS), revealed diuron and diazinon as the most ubiquitous and abundant compounds with levels up to 818 and 132 ng L 1, respectively. Total pesticide concentrations, which in only 1 out of 66 samples surpassed 500 ng L 1, were higher in the tributaries than in the river but their contribution in terms of mass-loads to the overall pesticide pollution of the Llobregat River was relatively small. Contamination increased downstream of the river and was clearly influenced by rainfall and hence river flow. Application of the PRISW-1 index indicated that, although pesticides levels fulfilled the European Union Environmental Quality Standards (EQS) for surface waters, the existing pesticide contamination poses a low to high ecotoxicological risk for aquatic organisms, that algae and macro-invertebrates are at higher risk than fish, and that the organophosphates diazinon and malathion and the phenylurea diuron are the major contributors to the overall toxicity and therefore the most problematic compounds.

In compliance with the requirements of the EU Water Framework Directive, monitoring of the ecological and chemical status of Catalan river basins (NE Spain) is carried out by the Catalan Water Agency. The large amount of data collected and the complex relationships among the environmental variables monitored often mislead data interpretation in terms of toxic impact, especially considering that even pollutants at very low concentrations might contribute to the total toxicity. The total dataset of chemical monitoring carried out between 2007 and 2008 (232 sampling stations and 60 pollutants) has been analyzed using sequential advanced modeling techniques. Data on concentrations of contaminants in water were pre-treated in order to calculate the bioavailable fraction, depending on substance properties and local environmental conditions. The resulting values were used to predict the potential impact of toxic substances in complex mixtures on aquatic biota and to identify hot spots. Exposure assessment with Species Sensitivity Distribution (SSD) and mixture toxicity rules were used to compute the multi-substances Potentially Affected Fraction (msPAF). The combined toxicity of the pollutants analyzed in the Catalan surface waters might potentially impact more than 50% of the species in 10% of the sites. In order to understand and visualize the spatial distribution of the toxic risk, Self Organising Map (SOM), based on the Kohonen's Artificial Neural Network (ANN) algorithm, was applied on the output data of these models. Principal Component Analysis (PCA) was performed on top of Neural Network results in order to identify main influential variables which account for the pollution trends. Finally, predicted toxic impacts on biota have been linked and correlated to field data on biological quality indexes using macroinvertebrate and diatom communities (IBMWP and IPS). The methodology presented could represent a suitable tool for water managers in environmental risk assessment and management.

During 8 sampling campaigns carried out over a period of two years, 72 samples, including influent and effluent wastewater, and sludge samples from three conventional wastewater treatment plants (WWTPs), were analyzed to assess the occurrence and fate of 43 pharmaceutical compounds. The selected pharmaceuticals belong to different therapeutic classes, i.e. non-steroidal anti-inflammatory drugs, lipid modifying agents (fibrates and statins), psychiatric drugs (benzodiazepine derivative drugs and antiepileptics), histamine H2-receptor antagonists, antibacterials for systemic use, beta blocking agents, beta-agonists, diuretics, angiotensin converting enzyme (ACE) inhibitors and anti-diabetics. The obtained results showed the presence of 32 target compounds in wastewater influent and 29 in effluent, in concentrations ranging from low ng/L to a few μg/L (e.g. NSAIDs). The analysis of sludge samples showed that 21 pharmaceuticals accumulated in sewage sludge from all three WWTPs in concentrations up to 100 ng/g. This indicates that even good removal rates obtained in aqueous phase (i.e. comparison of influent and effluent wastewater concentrations) do not imply degradation to the same extent. For this reason, the overall removal was estimated as a sum of all the losses of a parent compound produces by different mechanisms of chemical and physical transformation, biodegradation and sorption to solid matter. The target compounds showed very different removal rates and no logical pattern in behaviour even if they belong to the same therapeutic groups. What is clear is that the elimination of most of the substances is incomplete and improvements of the wastewater treatment and subsequent treatments of the produced sludge are required to prevent the introduction of these micro-pollutants in the environment.

The present work describes the development of a fully automated method, based on on-line solid-phase extraction (SPE)–liquid chromatography-electrospray–tandem mass spectrometry (LC–MS–MS), for the determination of 74 pharmaceuticals in environmental waters (superficial water and groundwater) as well as sewage waters. On-line SPE is performed by passing 2.5 mL of the water sample through a HySphere Resin GP cartridge. For unequivocal identification and confirmation two selected reaction monitoring (SRM) transitions are monitored per compound, thus four identification points are achieved. Quantification is performed by the internal standard approach, indispensable to correct the losses during the solid phase extraction, as well as the matrix effects. The main advantages of the method developed are high sensitivity (limits of detection in the low ng L−1 range), selectivity due the use of tandem mass spectrometry and reliability due the use of 51 surrogates and minimum sample manipulation. As a part of the validation procedure, the method developed has been applied to the analysis of various environmental and sewage samples from a Spanish river and a sewage treatment plant., This work has been supported by the Spanish Ministry of Science and Innovation [projects CGL2007-64551/HID, Consolider-Ingenio 2010 CSD2009-00065] and the Unity Through Knowledge Fund (UKF), which was established by the Croatian Ministry of Science, Education and Sports through the World Bank Loan No. 7320-HR. Merck is acknowledged for the gift of LC columns and Spark Holland for the gift of on-line SPE cartridges. Rebeca López Serna acknowledges the Spanish Ministry of Education and Science for the economical support through the FPI pre-doctoral grant.

In a long term study, which covered 4 sampling periods over three years, a total number of 84 samples, specifically 28 influent, effluent, from seven WWTP located in the main cities along the Ebro river Basin (North East of Spain), as well as receiving river waters, were analyzed to assess the occurrence of 73 pharmaceuticals covering several medicinal classes. Results indicated that pharmaceuticals are widespread pollutants in the aquatic environmental. Linking the calculation of removal rates with half-lives, assuming that compound degradation followed pseudo-first order kinetics, suggested that conventional wastewater treatments applied at the seven WWTP were unable to completely remove most of the pharmaceuticals under study. The evaluation of compound degradability, in terms of half-lives, is an important task to discuss integrated solutions for mitigation of pollutants entry into the water cycle. High half-lives observed for the majority of pharmaceuticals in WWTP suggest that, in order to enhance compound degradation, higher hydraulic retention times should be required. The wide spectrum of substances detected in receiving river waters indicates that WWTP outlets are major contributors of pharmaceuticals in the aquatic environment. However, municipal wastewater treatment represents an obligatory and final treatment step prior to their release into the aquatic media, since load of pharmaceuticals in outlets were considerably reduced after treatment. Finally, hazard posed by pharmaceuticals in both surface and effluent wastewaters was assessed toward different aquatic organisms, (algae, daphnids and fish). The overall relative order of susceptibility was estimated to be algae > daphnia > fish. Results indicate that no significant risks could be associated to the presence of pharmaceuticals in those matrices, indicating that reduction of compound concentration after wastewater treatment as well as dilution factor once pharmaceuticals are discharged in receiving river water efficiently mitigate possible environmental hazards., EU project AQUATERRA (GOCE 505428) and the Spanish Ministry of Science and Education Project CEMAGUA (CGL2007-64551)

Pharmaceuticals are designed to improve human and animal health, but even the most beneficial pharmaceuticals might raise some questions concerning the consequences of exposure to non-target organisms. To illustrate this situation and using diclofenac as a case-study, we analyze global consumption and occurrence data to identify hot spots of consumption without occurrence data, review the scientific literature on the harmful environmental effects to determine whether the observed concentrations in freshwater are of environmental concern, summarize the current pharmaceutical and environmental policies to highlight policy gaps, and suggest a series of research and policy recommendations, which can be summarized as follows: we need to improve the current knowledge on occurrence in freshwaters to properly implement environmental policies (i), diclofenac might pose a risk to non-target organisms in freshwater (ii); the harmful effects that some pharmaceuticals may have on the environment are not always addressed by environmental policies (iii). Keywords: Diclofenac, Pharmaceuticals, Environmental risks, Ecotoxicity, Freshwater ecosystems, Environmental policies

15 pages, 9 figures, 2 tables.-- PMID: 16762399 [PubMed].-- Printed version published Dec 1, 2006., Chemometric methods are applied in the analysis and interpretation of large multivariate data sets obtained in environmental monitoring studies. Multiple fish and sediment river samples from different sampling sites at different geographical locations and during different campaigns and/or sampling time periods were collected and analyzed as a part of an extensive multi annual monitoring program. Concentrations of organic microcontaminants (like hexachlorobenzene, hexachloro-butadiene, hexachlorocyclohexane, dichloro-diphenyldichloroethane and metabolites, and polychlorinated biphenyls PCBs, among others) were determined in fish and sediment river samples from Catalonia (northeast Spain). Chemometrics modeling and interpretation of these data sets allowed the investigation of the main contamination patterns in the rivers under study and the investigation of their distribution. The results achieved in this study are intended to be a contribution to quality assessment and evaluation of the global situation of the contamination of surface waters in Catalonia, and to support public policies of environmental control and protection in the region under study., Research project No. BQU2003-00191 from MCyT, Spain, is acknowledged. E. Peré-Trepat thanks her PhD grant from Universitat de Barcelona and Catalan Water Agency (Agència Catalana de l'Aigua).

Headspace (HS) gas chromatography with flame ionisation detection (HS-GC-FID) and purge and trap (P) gas chromatography-mass spectrometry (P) were used for the determination of methyl-tert-butyl ether (MTBE) and benzene, toluene, and xylenes (BTEX) in groundwater. In this work, we present the first data on the levels of MTBE and BTEX in different groundwater wells in the area of Catalonia (northeast Spain). This monitoring campaign corresponded to 28 groundwater wells that were located near petrol service stations, oil refinery storage tanks, and/or chemical industry at different locations of Catalonia during the period of 1998/1999. The levels of MTBE detected varied between 4—300 μg/l, but two sites had MTBE levels up to 3 and 13 mg/l. In many cases, the BTEX levels were below 1 μg/l, whereas 7 sites had levels varying from 19 μg/l up to 3 mg/l. Most of them were related to leakage from underground tanks in petrol service stations, while the remaining three corresponded respectively to chemical industrial pollution of undetermined origin and to a leak from high-ground petrol tanks in petrochemical refinery factories. The aquifers involved were constituted by detritus coarse materials, sands, and conglomerates. Piezometric levels were roughly comprised between 3 and 40 m, and permeability (K) and transmissivity (T) values were estimated from field measurements.The MTBE/BTEX ratio was also calculated and reached values up to 250. These values were expected, since if we consider that spilled oxygenated gasoline is the source of well contamination and based on solubility considerations alone, the MTBE source concentrations would be about 200 times higher than any BTEX compounds.

The use of chemicals is continuously growing both in total amount as well as in a number of different substances, among which organic chemicals play a major role. Owing to the growing public awareness on the need of protecting both ecosystems and human health from the risks related to chemical pollution, an increasing attention has been drowned to risk assessment and prioritization of organic pollutants. In this context, the aims of this study were (a) to perform an environmental risk assessment for 200 organic micropollutants including both regulated and emerging contaminants (pesticides, alkylphenols, pharmaceuticals, hormones, personal care products, perflourinated compounds and various industrial organic chemicals) monitored in four rivers located in the Mediterranean side of the Iberian Peninsula, namely, the Ebro, Llobregat, Júcar and Guadalquivir rivers; and (b) to prioritize them for each of the four river basins studied, taking into account their observed concentration levels together with their ecotoxicological potential. For this purpose, a prioritization approach has been developed and a resulting ranking index (RI) associated with each compound. Ranking index is based on the measured concentrations of the chemical in each river and its ecotoxicological potential (EC50 values for algae, Daphnia sp. and fish). Ten compounds were identified as most important for the studied rivers: pesticides chlorpyriphos, chlorfenvinphos, diazinon, dichlofenthion, prochloraz, ethion carbofuran and diuron and the industrial organic chemicals nonylphenol and octylphenol that result from the biodegration of polyethoxylated alkyphenol surfactants. Also, further research into chronic toxicity of emerging contaminants is advocated Thisworkwas funded by the SpanishMinistry of Economy and Competitiveness project Consolider-Ingenio 2010 SCARCE CSD2009-00065 and by the Generalitat de Catalunya (Consolidated Research Groups “2014 SGR 418–Water and Soil Quality Unit” and 2014 SGR 291–ICRA)

Chemometric methods are applied to the analysis and interpretation of large multivariate data sets obtained in environmental monitoring studies. Concentrations of multiple organic compounds were measured in river samples taken from several sampling sites, at various geographical locations, during a number of campaigns and/or sampling time periods. Samples were collected and analyzed as part of an extensive multi-annual monitoring program from a mediterranean river basin (in Catalonia, at the northeast of Spain) by the Water Quality Regional Agency. Due to the great amount of multivariate data stored in environmental databases and to their complexity, chemometric modeling methods like Principal Components Analysis (PCA) and Multivariate Curve Resolution with Alternating Least-Squares (MCR-ALS) coupled to appropriate mapping representations are proposed for the evaluation of the environmental quality of the studied rivers. Results achieved in this study are intended to be a contribution to water quality assessment and evaluation of contamination of surface waters in river basin, and to support public policies of environmental control and management of the regions under study. Fil: Garcia Reiriz, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentina Fil: Olivieri, Alejandro Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentina Fil: Teixidó, Elisabeth. Agència Catalana de l’Aigua; España Fil: Ginebreda, Antoni. Consejo Superior de Investigaciones Científicas. Instituto de Diagnóstico Ambiental y Estudios del Agua; España Fil: Tauler, Romà. Consejo Superior de Investigaciones Científicas. Instituto de Diagnóstico Ambiental y Estudios del Agua; España

Mediterranean rivers are characterized by highly variable hydrological regimes that are strongly dependent on the seasonal rainfall. Sediment transport is closely related to the occurrence of flash-floods capable to deliver enough kinetic energy to mobilize the bed and channel sediments. Contaminants accumulated in the sediments are likely to be mobilized as well during such events. However, whereas there are many studies characterizing contaminants in steady sediments, those devoted to the transport dynamics of suspended-sediment borne pollution are lacking. Here we examined the occurrence and transport of persistent organic microcontaminants present in the circulating suspended sediments during a controlled flushing flow in the low part of the River Ebro (NE Spain) 12km downstream of a well-known contaminated hot-spot associated to a nearby chloro-alkali industry. Polycyclic aromatic hydrocarbons (PAHs) and semi-volatile organochlorine pollutants (DDT and related compounds, DDX; polychlorinated byphenils, PCBs; and other organochlorine compound, OCs) were measured in the particulate material by GC-MS and GC-MS/MS, using previously developed analytical methods. The concentration levels observed were compared to previously reported values in steady sediments in the same river and discussed on a regulatory perspective. Hydrographs and sedigraphs recorded showed a peak-flow of 1300m3s-1 and a corresponding peak of suspended sediments of 315mgL-1. Combination of flow discharge, suspended sediments and pollutants' concentrations data allowed for quantifying the mass flows (mass per unit of time) and setting the load budgets (weight amount) of the different pollutants transported by the river during the monitored event. Mean mass-flows and total load values found were 20.2mgs-1 (400g) for PAHs, 38mgs-1 (940g) for DDX, 44mgs-1 (1038g) for PCBs and 8mgs-1 (200g) for OCs. The dynamic pattern behavior of PAHs differs substantially to that of organochlorine pollutants, thus reflecting different pollution origins., This work was supported by the Spanish Ministry of Economy and Competitiveness through the Consolider-Ingenio 2010 project SCARCE (CSD2009-00065) and by the Generalitat de Catalunya (Consolidated Research Group: Water and Soil Quality Unit 2009-SGR-965). The research leading to these results has received funding from the European Comunities 7th Framework Programme under Grant Agreement No. 603629-ENV-2013-6.2.1-Globaqua.

The hazard of chemical compounds can be prioritized according to their PBT (persistence, bioaccumulation, toxicity) properties by using Self-Organizing Maps (SOM). The objective of the present study was to develop an Integrated Risk Index of Chemical Aquatic Pollution (IRICAP), useful to evaluate the risk associated to the exposure of chemical mixtures contained in river waters. Four Spanish river basins were considered as case-studies: Llobregat, Ebro, Jucar and Guadalquivir. A SOM-based hazard index (HI) was estimated for 205 organic compounds. IRICAP was calculated as the product of the HI by the concentration of each pollutant, and the results of all substances were aggregated. Finally, Pareto distribution was applied to the ranked lists of compounds in each site to prioritize those chemicals with the most significant incidence on the IRICAP. According to the HI outcomes, perfluoroalkyl substances, as well as specific illicit drugs and UV filters, were among the most hazardous compounds. Xylazine was identified as one of the chemicals with the highest contribution to the total IRICAP value in the different river basins, together with other pharmaceutical products such as loratadine and azaperol. These organic compounds should be proposed as target chemicals in the implementation of monitoring programs by regulatory organizations.

Pesticide usage in Delta del Ebro (NE Spain) during the rice growing season has been associated with oyster episodes of mortality that occur early in summer. However, there are no studies that have directly evaluated pesticide levels and effects in oysters (Crassotrea gigas) cultured in Ebro's Bays. In this study pesticide levels in water, metal body burdens and up to 12 different biochemical markers were monitored in gills and digestive glands of oysters transplanted from May to June in 2008 and 2009. Biochemical responses evidenced clear differences in oysters from 2008 and 2009. Oysters transplanted in 2009 showed their antioxidant defenses unaffected from May to June and consequently increased levels of tissue damage measured as lipid peroxidation and DNA strand breaks and of mortality rates. Conversely oysters transplanted in 2008 increase their antioxidant defenses from May to June, had low levels of lipid peroxidation and DNA damage and low mortality rates. Some pesticides in water such as bentazone and propanil together with high temperatures and salinity levels were related with tissue damage in oyster transplanted in 2008 but the observed large differences between years indicate that abiotic factors alone could not explain the high mortalities observed in 2009. An analysis of recent reported studies pointed out in the direction that in addition to abiotic factors the use of oysters sensitive to diseases may explain the observed responses.

This paper presents a new methodology to assess the risk of water effluents from waste-water treatment plants (WWTPs) based on fuzzy logic, a well-known theory to deal with uncertainty, especially in the environmental field where data are often lacking. The method has been tested using the effluent's pollution data coming from 22 waste-water treatment plants (WWTPs) located in Catalonia (NE Spain). Thirty-eight pollutants were analyzed along three campaigns performed yearly from 2008 to 2010. Whereas 9 compounds have been detected in more than 70% of the samples analyzed, 7 compounds have been found at levels equal or higher than the river Environmental Quality Standards set by the Water Framework Directive. Upon combination of both criteria (presence and concentration), compounds of greatest environmental concern in the WWTP studied are nickel, the herbicide diuron, and the endocrine disruptors nonyl and octylphenol. It is remarkable the low variability of the pollutant concentration just differing for the case of nickel and zinc. These low values of exposure together with other pollutants' characteristics provide a medium or low risk assessment for all the WWTPs. The results of this new method have been compared with COMMPS procedure, a solid method developed in the context of the Water Framework Directive, and they show that the fuzzy model is more conservative than COMMPS. This is due to different reasons: the fuzzy model takes into account the persistence of chemical compounds whereas COMMPS does not; the fuzzy model includes the weights provided by an expert group inquired in previous works and also considers the uncertainty of the environmental data, avoiding the crisp values and offering a range of overlapping between the different fuzzy sets. However, the results even if being more conservative with fuzzy logic, are in good agreement with a solid methodology such as the COMMPS procedure.

The Llobregat River, which is characterized by important fluctuations of the flow rates, receives treated waters from WWTPs. During the years 2007 and 2008, the Llobregat River basin suffered from a severe drought which affected the supply of drinking water facilities (DWF) that rely on the exploitation of the river water. The Catalan Water Agency implemented a water reuse experiment with the objective of maintaining the river flow rate at sufficiently high level so as to ensure the supply of raw water to Barcelona's major DWF.A total of 103 emerging contaminants belonging to the groups of pharmaceuticals (74), illicit drugs (17) and oestrogens (12) were determined using LC-MS/MS methods in river water samples during the water reuse campaign. The effect of the reclaimed water discharge on the river water quality, in terms of contamination loads and environmental risk (based on the concentration addition mode), is discussed.Fifty-eight pharmaceuticals out of 74 monitored were detected at least in one sample. In river water upstream (site R0) majority of compounds were detected at low nanograms per litre levels, while downstream of discharge of tertiary effluent only few compounds were detected at levels higher than 100 ng L(-1) (i.e. acetaminophen, diclofenac, erythromycin, sulfamethazine), but never exceeding 500 ng L(-1). The total concentration of illicit drugs was found to be very low at both sampling sites (50 ng L(-1)). No relevant ecotoxicity risks were identified, except for pharmaceuticals vs. algae.In general, the discharge of reclaimed water in the river influenced perceptibly in terms of concentrations, mass loads and environmental risk, especially for pharmaceuticals and in less extent for illicit drugs. Nevertheless, it was not very significant in any case.

Lists of compounds resulting from environmental monitoring may be conveniently represented in a very general way using Pareto distributions, after ranking them on descending order according to their concentration or hazard quotient expressed as percentages, depending on whether the objective of the monitoring is focussed on mass load occurrence or risk assessment respectively.Ranked distributions are characterized using appropriate indexes, such as h (Hirsch), well known in other disciplines like bibliometry. Furthermore, to such ordered distributions, simple numerical power type equations relating rank order and occurrence probability can be fitted, following the so-called power or Zipf law. Both h indices and the characteristic power law exponents are interpreted as measures of complexity of the overall mixture. On the other hand, compounds included within the h index may be seen as the most relevant in the mixture, thus providing a reasonable indication of what is worth analyzing. These concepts have been applied, as case study, to the characterization of the pharmaceutical compounds found in the input and output streams of wastewater treatment plants.Whereas both the concentration load and ecotoxicity of pharmaceuticals in WWTPs obviously decrease in the output of the treatment (influent effluent, sludge), complexity quantified using the proposed indexes does not follow the same trend, being this behaviour common to the three plants examined.The joint combination of h compounds of the three plants studied allowed optimizing the list of compounds to be analyzed, which must be considered the key ones for the scenario under study.

Given the huge number of chemicals released into the environment and existing time and budget constraints, there is a need to prioritize chemicals for risk assessment and monitoring in the context of the European Union Water Framework Directive (EU WFD). This study is the first to assess the risk of 500 organic substances based on observations in the four European river basins of the Elbe, Scheldt, Danube and Llobregat. A decision tree is introduced that first classifies chemicals into six categories depending on the information available, which allows water managers to focus on the next steps (e.g. derivation of Environmental Quality Standards (EQS), improvement of analytical methods, etc.). The priority within each category is then evaluated based on two indicators, the Frequency of Exceedance and the Extent of Exceedance of Predicted No-Effect Concentrations (PNECs). These two indictors are based on maximum environmental concentrations (MEC), rather than the commonly used statistically based averages (Predicted Effect Concentration, PEC), and compared to the lowest acute-based (PNECacute) or chronic-based thresholds (PNECchronic). For 56% of the compounds, PNECs were available from existing risk assessments, and the majority of these PNECs were derived from chronic toxicity data or simulated ecosystem studies (mesocosm) with rather low assessment factors. The limitations of this concept for risk assessment purposes are discussed. For the remainder, provisional PNECs (P-PNECs) were established from read-across models for acute toxicity to the standard test organisms Daphnia magna, Pimephales promelas and Selenastrum capricornutum. On the one hand, the prioritization revealed that about three-quarter of the 44 substances with MEC/PNEC ratios above ten were pesticides. On the other hand, based on the monitoring data used in this study, no risk with regard to the water phase could be found for eight of the 41 priority substances, indicating a first success of the implementation of the WFD in the investigated river basins. © 2011 Elsevier B.V., The presented prioritization approach was developed within the NORMAN Association (No. W604002510) working group on prioritization of emerging substances (WG 1) and was approved by the WG members present at the WG meeting in Paris (22–23 November 2010). The work was supported by the European Commission through the Integrated Projects MODELKEY (Contract-No. 511237GOCE) and OSIRIS (contract No. 037017). Peter C. von der Ohe was financially supported through a Deutsche Forschungsgemeinschaft (DFG) postdoctoral fellowship (PAK 406/1). The authors would like to acknowledge the International Commission for the Protection of the Danube River and the team of experts and laboratories providing the data from the Joint Danube Survey 2 as well as the Landesbetriebes für Hochwasserschutz und Wasserwirtschaft Sachsen-Anhalt (Gen. LHW/5.4/003/2006), the Sächsisches Landesamt für Umwelt und Geologie (LfUG, Dresden, Germany), the Vlaamse Milieumaatschappij (VMM, Erembodegem, Aalst, Belgium) and the Agencia Catalana de l'Aigua (ACA, Barcelona, Spain) who kindly provided the monitoring data used for the application of the methodology. Emma L. Schymanski is thanked for valuable suggestions that improved the manuscript.

In order to study the pollution of fluvial ecosystems, it is necessary to analyze not only the levels of chemical contaminants in water, but also those accumulated in the sediment matrix, as well as to assess its ecotoxicological status. Eleven Catalan (Spain) river sections (one sampling point per river) located near urban and industrial areas were sampled during winter of 2009. Water pollutants were collected by using passive samplers as Diffusive Gradient in Thin-Films (DGTs) and Semi-Permeable Membrane Devices (SPMDs). Point water samples were also collected. The concentrations of potentially toxic elements (PTE) in water, filtered water, DGTs and sediment samples were analyzed. Aqueous and organic solvent extracts of sediments samples and organic extracts of SPMDs were performed to assess acute toxicity to Vibrio fischeri by Microtox®, and chronic toxicity to the green alga Pseudokirschneriella subcapitata. Microtox® test was also performed with DGT extracts. The results show that metals content of Catalan river waters are below the freshwater screening US EPA benchmarks, excepting some industrial areas (for Hg, Pb, and Zn). In contrast, sediments levels of some rivers were far above freshwater sediment screening US EPA benchmarks (for Zn, As, Cr, Pb, Ni, Hg, and Mn), particularly in the most industrialized areas. A good correlation was found between toxicity values of extracts (from sediments and DGTs) and PTE levels in sediments. The current results support the suitability of using combined point and passive sampling methods for assessing the chemical and ecotoxicological status of aqueous environments. Keywords: River pollution, Heavy metals, Ecotoxicity, DGTs (Diffusive Gradient in Thin-Films), SPMDs (Semi-Permeable Membrane Devices)

Continuous input of pharmaceuticals into rivers, through wastewater treatment systems, may cause adverse effects on the aquatic ecosystems of the receiving waterbodies, due to the intrinsic biological activity of these compounds. To investigate this issue, we have carried out an Environmental Risk Assessment in the lower part of the Llobregat River basin (NE Spain). The survey was carried out along three campaigns in 7 sampling points, located in the main river and in one of its tributaries (Anoia River). In each sample, 29 commonly used pharmaceuticals, belonging to different therapeutical classes (analgesics and non-steroidal anti-inflammatories (NSAIDs), lipid regulators, psychiatric drugs, anti-histamines, anti-ulcer agents, antibiotics and β-blockers) have been determined. Simultaneously, the macroinvertebrate community status of the same points has been also studied. Hazard quotient indexes have been estimated for the most representative compounds as the ratio between concentrations and EC50 reported values, for three bioassays commonly used in environmental toxicology, namely, fish, Daphnia and algae. Hazard indexes are obtained for each sample by summing up the hazard quotients of all the compounds present, and taking its average along the three sampling campaigns. In general, hazard quotients tend to increase when going downstream. Only those points located most upstream of the two rivers can be qualified under low risk for the three bioassays. The most sensitive bioassay seems to be algae, followed by Daphnia and fish. Log-transformed hazard indexes show fairly good inverse correlations (r = − 0.58 to − 0.93, p < 0.05) with Shannon diversity indexes of macroinvertebrates, determined from both densities and biomasses. Best correlations are obtained for Daphnia based hazard indexes, as expected from its taxonomical proximity to macroinvertebrates. The abnormal correlation behaviour found in one point located in the Anoia River is explained by the presence of other previously reported pollutants of industrial origin, generated by the nearby existing industry., European Commission through the Integrated Project MODELKEY (Contract-No. 511237-GOCE) and by the Spanish Ministry of Science and Innovation through the project CEMAGUA (CGL2007-64551/HID).

The well established risk assessment COMMPS methodology (Fraunhofer Institut, Schmallenberg, Germany) developed at a European basin scale to identify priority pollutants based on their exposure and effects, has been applied at a local scale along a double step process: (a) first, the corresponding adapted list of priority pollutants has been obtained from monitoring data at a regional scale; (b) second, a new site pollution risk index has been developed for the relative comparison of the chemical pollution status of the investigated geographical region. As a case study, representative of the Mediterranean area, the process has been applied to 17 Catalan rivers (NE Spain), using the monitoring data collected between 1997 and 2006 in 207 different sampling sites. After an appropriate selection procedure, 52 parameters were finally used for the calculation of the local priority substance and site risk indexes. From the exposure point of view the most relevant substances at the Catalan scale were volatile organohalogen compounds (VOX) and volatile aromatic hydrocarbons (toluene and xylene), whereas the priority substance risk index points to dibromomethane (volatile organohalogen compound) and benzo-a-anthracene (PAH) as the most concerning compounds. The local and European priority substance indexes have been compared, showing minor differences. Finally, site risk indexes have been calculated and utilized for comparison of the chemical status of different sites. They can be conveniently displayed in quality geographical maps and are considered a valuable tool for the environmental management and risk assessment of the region under study., We are grateful to the Catalan Water Agency (Agencia Catalana de l’Aigua, ACA) for allowing access to monitoring data and to Ministerio de Ciencia e Inovación, Spain, for the CTQ2009-11572 research grant.

A wide range of human pharmaceuticals are present at low concentrations in freshwater systems, particularly in sections of polluted river. These compounds show high biological activity, often associated with a high stability. These characteristics imply a potential impact of these substances on aquatic biota even when present at low environmental concentrations. Low flow conditions in Mediterranean rivers, most of which flow through densely populated areas and are subjected to intensive water use, increase the environmental risk of these emergent compounds. Here, we studied whether pharmaceuticals in river water affect the local benthic community structure (diatoms and invertebrates). For this purpose, we analyzed the occurrence of pharmaceuticals along the Llobregat River and examined the benthic community structure (diatoms and invertebrates) of this system. Some pharmaceutical products in the Llobregat River registered concentrations greater than those cited in the literature. Multivariate analyses revealed a potential causal association between the concentrations of some anti-inflammatories and beta-blockers and the abundance and biomass of several benthic invertebrates (Chironomus spp. and Tubifex tubifex). Further interpretation in terms of cause-and-effect relationships is discussed; however, it must be always taken with caution because other pollutants also may have significant contributions. Combined with further community experiments in the laboratory, our approach could be a desirable way to proceed in future risk management decisions.

11 pages, 3 figures, 2 tables.-- PMID: 16959291 [PubMed].-- Online version available Sep 7, 2006., Three biomarkers of hydrocarbon exposure, liver 7-ethoxyresourfin-O-deethylase activity (EROD), fluorescent hydrocarbon compounds (FACs) in bilis, and the liver antioxidant enzyme catalase (CAT) were examined in the autochthonous fish species Barbus meridionalis collected in the river Fluvià (NE Catalunya, Spain) after an oil spillage. Four different locations were sampled, including the impacted site, upstream and downstream sites and a reference site. Biomarker responses were compared with diatom and macroinvertebrate community assemblage metrics (Specific Pollution Sensitivity index – IPS, and Iberian Biological Monitoring Working Party – IBMWP, respectively). Chemical analyses denoted that polycyclic aromatic hydrocarbon levels in sediment were much higher at the impacted site than in downstream reaches. Four fold increase of EROD activity together with increased levels of biliary FACs in barbs collected at the spilled site indicated exposure of inhabiting fish to the oil. Additionally, CAT activity was significantly depressed (four fold) when compared to other stations, thus suggesting that fish collected from the impacted sites could be more susceptible to suffer oxidative stress. Biological indices (particularly that of the diatom community IPS) showed slight significant effects between control and impacted sites, indicating that more tolerant taxa were favoured because of the oil spillage. These results support the need to include biochemical responses measured in local species in monitoring programmes aimed to diagnose specific pollution effects in stressed river ecosystems., This study was supported by the Catalan Water Agency (CWA) and the Spanish Project CGL2004-03514/HD. The authors thanks to Jaume Serrano and Anna Tarrats (CWA) for their valuable assistance in electric fish sampling.

14 pages, 5 figures, 4 tables.-- PMID: 12800934 [PubMed].-- Available on line May 8, 2003.-- Erratum published in: Journal of Chromatography A 1007(1-2): 209-210 (Jul 25, 2003)., In Catalonia (northeast Spain), a monitoring program was carried out to determine methyl tert.-butyl ether (MTBE), its main degradation products, tert.-butyl alcohol (TBA), tert.-butyl formate (TBF), and other gasoline additives, the oxygenate dialkyl ethers ethyl tert.-butyl ether, tert.-amyl methyl ether and diisopropyl ether and the aromatic compounds benzene, toluene, ethylbenzene and xylene (BTEX) in 21 groundwater wells that were located near different gasoline point sources (a gasoline spill and underground storage tank leakage). Purge-and-trap coupled to gas chromatography–mass spectrometry was optimised for the simultaneous determination of the above mentioned compounds and enabled to detect concentrations at ng/l or sub-μg/l concentrations. Special attention was given to the determination of polar MTBE degradation products, TBA and TBF, since not much data on method performance and environmental levels are given on these compounds in groundwater. All samples analysed contained MTBE at levels between 0.3 and 70 μg/l. Seven contaminated hot spots were identified with levels up to US Environmental Protection Agency drinking water advisory (20–40 μg/l) and a maximum concentration of 670 μg/l (doubling the Danish suggested toxicity level of 350 μg/l). Samples with high levels of MTBE contained 0.1–60 μg/l of TBA, indicating (but not proving) in situ degradation of parent compound. In all cases, BTEX was at low concentrations or not detected showing less solubility and persistence than MTBE. This fact confirms the suitability of MTBE as a tracer or indicator of long-term gasoline contamination than the historically used BTEX., This research is part of the WATCH (EVK1-CT-2000-00059) EU project funded by the EU Environment and Sustainable Development sub-program and from the Ministerio de Ciencia y Tecnología (REN2001-5039-E).

In the present work a combined analytical method involving toxicity and liquid chromatography–electrospray ionization-mass spectrometry (LC–ESI-MS) was developed for the determination of pharmaceutical compounds in water samples. The drugs investigated were the analgesics: ibuprofen, ketoprofen, naproxen, and diclofenac, the decomposition product of the acetyl salicylic acid: salicylic acid and one lipid lowering agent, gemfibrozil. The selected compounds are acidic substances, very polar and all of them are analgesic compounds that can be purchased without medical prescription. The developed protocol consisted, first of all, on the use Microtox® and ToxAlert®100 toxicity tests with Vibrio fischeri for the different pharmaceutical drugs. The 50% effective concentration (EC50) values and the toxicity units (TU) were determined for every compound using both systems. Sample enrichment of water samples was achieved by solid-phase extraction procedure (SPE), using the Merck LiChrolut® EN cartridges followed by LC–ESI-MS. Average recoveries loading 1 l of samples with pH=2 varied from 69 to 91% and the detection limits in the range of 15–56 ng/l. The developed method was applied to real samples from wastewater and surface-river waters of Catalonia (north-east of Spain). One batch of samples was analyzed in parallel also by High Resolution Gas Chromatography coupled with Mass Spectrometry (HRGC–MS) and the results have been compared with the LC–ESI-MS method developed in this work.

The aim of this communication is to provide preliminary results on MTBE monitoring, and at the same time to propose some new tracers of gasoline pollution in groundwater. An overview is presented on benzene-toluene-ethylbenzene-xylene (BTEX), methyl tertiary-butyl ether (MTBE), and dicyclopentadienes (DCPD) contents in gasoline formulations. Their specific fate in gasoline-contaminated aquifers are consistent with their physical-chemical properties.

The Llobregat is a Mediterranean river that is severely impacted by anthropogenic pressures. It is characterized by high flow variability which modulates its chemical and biological status. The present work evaluates the effects of flow changes on the concentration of pharmaceutically active compounds (PhACs) and their relationship to cellular parameters of river biofilms. To this end, at two selected sampling sites at the lower course of the Llobregat river, surface water samples were collected twice a week over two hydrologically different periods exhibiting low and high river flows. Higher levels of PhACs were detected at the downstream sampling site. Irrespective of the flow regime, analgesics, anti-inflammatories and lipid regulators were the most abundant substances at both sampling sites with total concentrations of up to1000 ng/L and 550 ng/L at the upstream and downstream sites, respectively. Antibiotics (fluoroquinolones) and psychiatric treatment drugs were also detected at high levels in the second campaign achieving concentrations of up to 500 ng/L. The principal component analysis (PCA) performed with the PhACs concentrations of the two campaigns revealed differences in the various therapeutic groups depending on sampling site and period. After a flash flood event during the second sampling period, dilution of PhACs occurred, but their average concentrations measured before the flood were restored within two weeks. For the majority of compounds, PhAC concentrations displayed an inverse relationship with river discharge The effects of water containing different concentrations of PhACs on biofilm communities were evaluated and related to flow regime variations. Translocation of biofilm communities from a less to a more polluted site of the river demonstrated an increase in bacteria mortality in the translocated biofilms. After the flood, extracellular peptidase activity and chlorophyll-a concentration were significantly reduced, and biofilm growth rate was significantly lower.

The determination of the real toxicity of sediments in aquatic ecosystems is challenging and necessary for an appropriate risk assessment. Different approaches have been developed and applied over the last several decades. Currently, the joint implementation of chemical, ecological and toxicological tools is recommended for an appropriate and successful toxicity risk assessment. We chose the combination of the toxic unit approach with acute pore water tests (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna) and whole-sediment exposure tests (V. fischeri, Chironomus riparius), together with invertebrate community composition (multivariate analyses) to detect short and long-term responses of the organisms in four rivers of the Iberian Peninsula. High toxicity was detected in three sites (the downstream sites of the Llobregat and the Júcar, and the most upstream site of the Ebro). We identified organophosphate insecticides and metals as the main variables responsible for this toxicity, particularly in the whole-sediment tests. In particular, chlorpyrifos was mostly responsible for the toxicity (TUs) of D. magna, coinciding with the C. riparius mortality (long-term toxicity) in the mentioned sites, and copper was the main pollutant responsible for the short-term toxicity of P. subcapitata. The combination of the different approaches allowed us to detect ecotoxicological effects in organisms and identify the main contributors to the toxicity in these multi-stressed rivers., This study was funded by the Spanish Ministry of Economics and Competitiveness (project Scarce, Consolider-Ingenio 2010 CDS2009- 00065) and the EC 7th Framework Programme (grant agreement 603629-ENV-2013.6.2-1 GLOBAQUA). We are especially grateful to Laura Armendáriz for the identification of the Oligochaeta, and to thosewho assisted us in the field and helped us to obtain data, especially, Júlio C. López-Doval and Patricia Rodrigo. Núria De Castro-Català holds a predoctoral grant from the University of Barcelona.