Spatial and temporal patterns of ecological risk induced by pesticides in Alqueva reservoir: a case study

The purpose of this study was to evaluate the potential impact of pesticides detected in the Alqueva reservoir (Guadiana Basin, South Iberian Peninsula) on the aquatic organisms belonging to this ecosystem. For this purpose, the occurrence and risk assessment of 25 pesticides, and of a number of their degradation products, were determined in the Alqueva surface waters. The target pesticides, which belonged to the classes of phenylureas, triazines, chloroacetanilides and organophosphorous, were analysed by isotope dilution on-line solid phase extraction-liquid chromatographytandem mass spectrometry. The aquatic risk assessment, which was based on the risk quotient method (RQ=MEC/PNEC; MEC: measured environmental concentrations; PNEC: predicted no-effect concentration) considered three trophic levels: algae, aquatic invertebrates and fish. The areas (sampling stations) most polluted by pesticides were Sra. Ajuda and Lucefecit, in the northern, and Álamos, in the middle portion of the reservoir. The aquatic risk assessment revealed that, from the various compounds analysed, terbuthylazine, chlorfenvinphos and diazinon presented nonacceptable risk. With the exception of terbuthylazine, that in two areas (Sra. Ajuda and Lucefecit) exhibited high risk (RQ > 1) under normal hydrological conditions, the high risk was only estimated in specific periods, with particularly high pesticide concentrations in the water column, that occurred after rainfall events during the period of pesticide application. The locations that had more samples with RQ > 1 were Sra. Ajuda followed by Lucefécit. The use of risk assessment allowed us to conclude that, despite that pesticides’ concentrations in the water column fulfill the European environmental quality standards, some compounds show a high ecotoxicological risk for aquatic organisms in the Alqueva ecosystem. The results demonstrate that, to have an efficient risk management process, the regulatory authorities of each country must consider an integrative chemical and ecotoxicological approach.info:eu-repo/semantics/publishedVersio

Microcosm experiments to control anaerobic redox conditions when studying the fate of organic micropollutants in aquifer material

      The natural processes occurring in subsurface environments have proven to effectively remove a number of organic pollutants from water. The predominant redox conditions revealed to be one of the controlling factors. However, in the case of organic micropollutants the knowledge on this potential redox-dependent behavior is still limited. Motivated by managed aquifer recharge practices microcosm experiments involving aquifer material, settings potentially feasible in field applications, and organic micropollutants at environmental concentrations were carried out. Different anaerobic redox conditions were promoted and sustained in each set of microcosms by adding adequate quantities of electron donors and acceptors. Whereas denitrification and sulfate-reducing conditions are easily achieved and maintained, Fe- and Mn-reduction are strongly constrained by the slower dissolution of the solid phases commonly present in aquifers. The thorough description and numerical modeling of the evolution of the experiments, including major and trace solutes and dissolution/precipitation of solid phases, have been proven necessary to the understanding of the processes and closing the mass balance. As an example of micropollutant results, the ubiquitous beta-blocker atenolol is completely removed in the experiments, the removal occurring faster under more advanced redox conditions. This suggests that aquifers constitute a potentially efficient alternative water treatment for atenolol, especially if adequate redox conditions are promoted during recharge and long enough residence times are ensured. &nbsp

Formation of diclofenac and sulfamethoxazole reversible transformation products in aquifer material under denitrifying conditions: Batch experiments

      Soil-aquifer processes have proven to work as a natural treatment for the attenuation of numerous contaminants during artificial recharge of groundwater. Nowadays, significant scientific effort is being devoted to understanding the fate of pharmaceuticals in subsurface environments, and to verify if such semipersistent organic micropollutants could also be efficiently removed from water. In this context we carried out a series of batch experiments involving aquifer material, selected drugs (initial concentration of 1 μg/L and 1 mg/L), and denitrifying conditions. Diclofenac and sulfamethoxazole exhibited an unreported and peculiar behavior. Their concentrations consistently dropped in the middle of the tests but recovered toward the end, which suggest a complex effect of denitrifying conditions on aromatic amines. The transformation products Nitro-Diclofenac and 4-Nitro-Sulfamethoxazole were detected in the biotic experiments, while nitrite was present in the water. Their concentrations developed almost opposite to those of their respective parent compounds. We conjecture that this temporal and reversible effect of denitrifying conditions on the studied aromatic amines could have significant environmental implications, and could explain at least partially the wide range of removals in subsurface environments reported in literature for DCF and SMX, as well as some apparent discrepancies on SMX behavior. &nbsp

Analysis of monitoring programmes and their suitability for ecotoxicological risk assessment in four Spanish basins

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.López Doval, JC.; De Castro Catala, N.; Andrés Doménech, I.; Blasco, J.; Ginebreda, A.; Muñoz, I. (2012). Analysis of monitoring programmes and their suitability for ecotoxicological risk assessment in four Spanish basins. Science of the Total Environment. 440:194-203. https://doi.org/10.1016/j.scitotenv.2012.07.035S19420344

Floating macro litter in European rivers - top items

The JRC exploratory project RIMMEL provides information about litter, mainly plastic waste, entering the European Seas through river systems. RIMMEL has collected data on riverine floating macro litter inputs to the sea. Data acquisition was based on the Riverine Litter Observation Network (RiLON) activities, which collected data from rivers in the European marine basins over a period of one year (September 2016 – September 2017). Data was collected by visual observations and documented with the JRC Floating Litter Monitoring Application for mobile devices, allowing a harmonized reporting, compatible with the MSFD Master List of Categories for Litter Items. This report includes the Top Items lists of riverine floating macro litter, based on the total amount of litter items identified during RiLON activities and ranked by abundance. Top Items lists have been elaborated considering the whole database for the European Seas and further detailed for each individual European regional sea: Baltic Sea, Black Sea, Mediterranean Sea and North-East Atlantic. The North-East Atlantic and the Mediterranean Sea regions showed similar litter categories in their Top 20 Items. These two regions provided most of the available data, influencing the general Top Items list. In the Black Sea and Baltic Sea regions, where data availability was limited, the Top Items lists showed more differences among the different regions. Overall, the general Top Items list for the European Seas showed a predominance of plastic item categories (artificial polymer materials). As a whole, plastic items made up to 80.8% of all objects, with plastic and polystyrene fragments comprising 45% of the identified items in the database. Additionally, Single Use Plastics such as bottles, cover/packaging and bags were also ranked among the most frequently found floating litter. The similarities in the Top 10 and Top 20 items for the different regions, and the appearance of Single Use Plastics scoring high in the ranking, support the need for common actions against plastic pollution at EU level.JRC.D.2-Water and Marine Resource

Plaguicidas polares en el medio ambiente: análisis, presencia y evaluación de riesgo

[spa] Durante esta Tesis Doctoral se ha evaluado la presencia de hasta 26 plaguicidas y productos de transformación (herbicidas, insecticidas y fungicidas) en aguas residuales, superficiales, subterráneas, potables y en sedimentos. También se ha evaluado el impacto ambiental de los plaguicidas a través de estudios de toxicidad, desarrollo de modelos de predicción y cálculo y elaboración de índices de riesgo ambiental (uno de ellos creado durante la Tesis Doctoral). Las metodologías analíticas desarrolladas se han basado en las técnicas online SPE-LC-ESI-MS/MS (para aguas) y PLE seguida de SPE y LC-ESI-MS/MS (sedimentos). Los métodos, han consistido en el uso del método de dilución isotópica lo que conlleva una elevada sensibilidad, alta selectividad y fiabilidad de resultados. Otras ventajas de los métodos son su versatilidad, su relativa simplicidad y su rapidez. Los estudios llevados a cabo en cuatro EDARs han puesto en evidencia no sólo la presencia de elevadas concentraciones de plaguicidas en aguas residuales de zonas urbanas (> 500 ng/L de plaguicidas individuales), sino también su deficiente eliminación durante el tratamiento en las plantas. Los tratamientos terciarios estudiados también se han mostrado ineficientes. El estudio de reutilización del agua llevado a cabo en el río Llobregat indica que el uso de aguas regeneradas en este río no afecta significativamente a la calidad del agua del mismo, ni tampoco al rendimiento de la potabilizadora que se encuentra en la región, por lo que esta práctica se presenta como una buena opción para contribuir a mantener el caudal del río y a garantizar el abastecimiento de agua potable a la ciudad de Barcelona. En aguas superficiales, los plaguicidas más ubicuos son el diazinón, el diurón y la terbutilazina mientras que en zonas agrícolas dedicadas al cultivo del arroz son el MCPA, la bentazona y el molinato. El malatión se detectó a elevadas concentraciones en el agua y también en moluscos. En aguas subterráneas, Lleida fue la zona del territorio catalán más afectada por la contaminación por plaguicidas, y las triazinas fueron los herbicidas más ubícuos. El estudio de recarga artificial ha mostrado que utilizando una capa reactiva (preparada fundamentalmente a base de compost) mejora la calidad del agua infiltrada, lo que la hace una tecnología útil y viable para aumentar el nivel freático con las consiguientes ventajas que ello implica. Los resultados obtenidos de plaguicidas en sedimentos guardan relación con el contenido de materia orgánica del sedimento y con las propiedades físico-químicas de los compuestos, como solubilidad, movilidad, potencial de bioacumulación y volatilidad. En general, todos los estudios de ERA realizados indican que los plaguicidas son una fuente de estrés importante para el medio acuático, y entre los compuestos estudiados destacan, por este orden, el diazinón, el malatión, el diurón, la terbutilazina, la simazina, la atrazina, el clortolurón y el isoproturón. Todos ellos están incluidos en la lista de compuestos prioritarios por la Comunidad Europea. Sobre lo modelos de predicción, el modelo de balance de flujo se mostró eficiente y útil, prediciendo con un margen de error inferior al 25% niveles de plaguicidas a unos 8 km de distancia del punto de referencia. En relación al estado general de las aguas, tomando como referencia las NCA más restrictivas (para aguas subterráneas), se ha visto que 19 de los 22 plaguicidas estudiados han superado en al menos un estudio el nivel de 100 ng/L, y el 16% de las muestras analizadas presentó un contenido de pesticidas totales superior a 500 ng/L.[eng] The presence of up to 26 pesticides and transformation products (herbicides, insecticides and fungicides) was evaluated in wastewater, surface water, groundwater, drinking water and sediment. Their environmental impact assessed through the performance of toxicity studies, the development of predictive models, and the calculation and design of environmental risk indices (one of them created during the Doctoral Thesis) was also evaluated. The developed methods were based on on-line solid phase extraction (SPE) and pressurized liquid extraction (PLE) for the analysis of water and sediment samples respectively, in both cases followed by liquid chromatographic analysis coupled to tandem mass spectrometry detection (LC-MS/MS). The use of the isotope dilution technique (with isotopically labeled compounds) for quantification of the pesticides allowed good validation parameters. The most ubiquitous pesticides in urban areas were diazinon, diuron and terbuthylazine. In rice growing areas MCPA, molinate and bentazone presented the highest ubiquity and concentrations. Malathion was also detected at high concentrations in both water samples and seafood in these areas. The presence of pesticides in groundwater in Catalonia was found to be determined not only by the activities conducted in the area, but also by the degree of soil irrigation, the GUS index and the depth of the water sampling points. Regarding artificial aquifer recharge, percolation through a reactive layer prepared with fresh compost during the recharge process increases the quality of the recharge water and can be used to treat and recover surface and eventually waste waters Studies conducted wastewater treatment plants (WWTPs) have highlighted not only the presence of high concentrations of pesticides in urban areas (> 500 ng/L of individual pesticides), but also their poor removal during wastewater treatment. Tertiary treatments were also evaluated, revealing the inefficiency of some treatments and consequently the poor quality of reclaimed waters. Finally, all environmental risk assessment (ERA) studies showed consistent and valuable results that evidenced the influence of pesticides on the quality status of the water bodies. All these studies point to pesticides as one stressors in the aquatic environment, especially 8 of them in the following order: diazinon, malathion, diuron, terbuthylazine, simazine, atrazine, isoproturon, and chlortoluron

Medium to highly polar pesticides in seawater: Analysis and fate in coastal areas of Catalonia (NE Spain)

Pollution has been less investigated in marine and coastal environments than in inland waters. The low levels at which pollutants are expected to be present in seawater calls for the use of reliable and high sensitivity analytical methodologies. In this context, this work presents the optimization and validation of an analytical method to determine 26 medium to highly polar pesticides in seawater based on solid phase extraction and liquid chromatography-tandem mass spectrometry detection. The developed methodology was linear, accurate (relative recoveries within 80–120% for most analytes), repeatable (relative standard deviations <18% for most analytes), and sensitive (limits of determination <1 ng/L for 89% of the compounds). The use of isotopically labeled compounds as surrogate standards compensated for low analyte recoveries and matrix effects. The method was applied to the analysis of seawater samples collected along the coastline of Catalonia (NE Spain). Overall, total pesticide loads were higher inside the marinas than outside. The booster biocides diuron and irgarol used in antifouling paintings and different triazine pesticides were the most abundant compounds. Irgarol was present above the maximum allowable concentration set in European regulations in 70% of the samples collected inside the marinas. A different pesticide pollution pattern, with MCPA and bentazone presenting the highest concentrations, was observed at the Ebro Delta area due to the impact of the agricultural activities carried out there. To the authors’ knowledge, 4 out of the 26 target pesticides, namely, chlorfenvinphos, fenthion oxon, fenthion sulfone, and fenthion sulfoxide, have not been previously investigated in seawater. © 2018 Elsevier LtdThis work has been financially supported by the EU FP7 through the SOLUTIONS project (FP7-ENV-2013, No. 603437), by the Ministry of Science, Innovation and Universities through the PLAS-MED project (CTM2017-89701C3-R), and by the Generalitat de Catalunya (Consolidated Research Group 2017 SGR 01404 - Water and Soil Quality Unit). Thanks to the Swedish University of Agricultural Sciences for its support through the August T Larsson Guest Researcher Programme. The authors would also like to express their gratitude to Cristina Bosch, Gabriella Schirinzi, Josep Sanchís, Mar Olmos and Samuel Jimenez for their assistance with sampling, and to Simon Monllor for his assistance with sample processing.Peer reviewe

Occurrence and potential risk of currently used pesticides in sediments of the Alqueva reservoir (Guadiana Basin)

The evaluation of sediments, concerning to pesticides, constitutes an important step for the understanding of the principal sources of contamination of the surface water. Hence, the purpose of this study was to evaluate for the first time the occurrence, distribution and risk of pesticides in sediments of the Alqueva reservoir, the largest reservoir in the Europe. For this purpose, the occurrence of 22 pesticides and some of their degradation products was determined in surficial sediments of the Alqueva reservoir. To assess the potential risk on ecosystem, the measured concentrations of pesticides were compared with regulatory and toxicological benchmarks. Of the 22 pesticides analysed, only 8 were detected. Diuron was the pesticide detected in greater concentration, followed by terbuthylazine and chlortoluron. The sediments most polluted by pesticides were from Lucefécit, constituted totally by fine particles (<0.063 mm) and with high values of organic matter, and are located nearby large agricultural fields. The risk assessment allowed us to conclude that the sediments from the Alqueva reservoir presented low risk, concerning to pesticides, for the various communities that integrate the aquatic ecosystems. However, some of the compounds detected present a high potential for bioaccumulation that may lead to their bioamplification in the trophic chain, reaching concentrations higher than their acceptable daily intake, putting, in this way the populations at risk