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

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

Riverine anthropogenic litter load to the Mediterranean Sea near the metropolitan area of Barcelona, Spain

Every year >4 million tonnes of plastic are estimated to enter the oceans and much of it comes from land-based sources through rivers and estuaries. To fill the lack of information related to plastic inputs from rivers, a harmonized approach based on visual observations for monitoring floating macro litter was followed in this work. We provide the results of one-year monitoring (October 2016–September 2017) in the Llobregat and El Besòs rivers, which are flowing through an industrialized and populated area nearby the city of Barcelona (Catalonia, NE Spain). Floating litter items categories were influenced by urban centres located along the rivers. Overall, similar litter composition was observed in both rivers with a prevalence of plastics, mainly related to the food and beverage sectors. Seasonal variability showed significant correlations with natural factors such as wind and rainfall. Approximately 0.4–0.6 tonnes of plastic per year were estimated to be loaded into the sea by these two Catalan rivers. This study contributes to enlarge our knowledge on anthropogenic riverine litter entering the NW Mediterranean Sea, providing a starting point for the development of further mitigation strategies

Risk assessment of pesticides detected in surface water of the Alqueva reservoir (Guadiana basin, southern of Portugal)

The purpose of this study was to evaluate the potential impact of the 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 areas (sampling stations) most polluted by pesticides were Sra. Ajuda, Lucefecit and Álamos in the northern and in the middle portions of the reservoir, respectively. The aquatic risk assessment revealed that from the various compounds analysed terbuthylazine, chlorfenvinphos and diazinon presented non-acceptable risk when maximum concentrations were used as the measured environmental concentrations (MEC). The locations that had more samples with risk quotients higher than 1 (high risk) were Sra. Ajuda followed by Lucefécit. The use of risk assessment allowed us to conclude that, despite that the pesticides' concentrations in the water column fulfil the European environmental quality standards, a number of the compounds show a high ecotoxicological risk for the aquatic organisms in the Alqueva ecosystem. The results thereby demonstrate that to have an efficient risk management process, the regulatory authorities of each country must consider an integrative chemical and ecotoxicological approach.Logistic support for sampling was provided by the Portuguese Environmental Agency (APA — Agência Portuguesa do Ambiente). Merck is acknowledged for the gift of LC columns

Riverine anthropogenic litter load to the Mediterranean Sea near the metropolitan area of Barcelona, Spain

Every year more than 4 million tons of plastic are estimated to enter in the oceans and much of it comes from the land by rivers or estuaries. Plastic residues persist and accumulate in the environment and they can easily interact with marine organisms. An important step to understand and alleviate the severe problem of marine litter is to fill the lack of information related to plastic inputs from rivers. In this frame, the RIMMEL project proposed a harmonised approach based on a visual observation for monitoring the floating macro litter transported from different European rivers into the marine environment. Quantifying mismanaged waste in freshwater inputs requires a complex previous study of the riverine area considering hotspots and possible sources. Herein, we provide the results of one year of monitoring (October 2016 - September 2017) in the Llobregat and El Besòs rivers, which are flowing through an industrialised and populated area nearby the city of Barcelona (Catalonia, NE Spain). Results highlighted that discharged items categories were influenced by urban centres located along the rivers. Overall, more than 50% of the identified floating litter items were plastics, mainly related to the food or beverage sectors. Approximately 0.4 tons of plastic per year were estimated to be loaded into the sea by these two Catalan rivers. Finally, this study contributes to enlarge our knowledge on anthropogenic riverine litter entering the NW Mediterranean Sea, providing a starting point for the development of further mitigation strategies.JRC.D.2-Water and Marine Resource

Fate and risk of pesticides, pharmaceuticals, illicit drugs, and personal care products in the Iberian river basins of Ebro and Llobregat: Challenges and solutions using advanced treatment technologies in a European context

Occurrence of emerging contaminants in environmental waters is directly related to their removal in wastewater treatment plants (WWTPs) and the flow rate of the receiving waters. Conventional WWTPs were not designed to remove some organic compounds such as emerging pollutants. A wide array of micropollutants are usually found in WWTP efluents, so there is a need to develop and evaluate alternative treatments which could be efficient for their elimination.Advanced treatment technologies such membrane bioreactors (MBR) and photocatalytic processes could improve the removal of many emerging pollutants and thereby diminish their presence in surface waters. Mediterranean rivers are characterized by important fluctuations in the flow rates and heavy contamination pressures from extensive urban, industrial and agricultural activities. This translates in contamination levels most often higher than in other European basins. For instance, the Llobregat river basin (Catalonia, NE Spain) suffers from extreme and frequent flow fluctuations (1–100 m3 s-1) and receives the effluent discharges of more than 55 WWTPs, and at some points, especially in drought periods, the effluents may represent almost 100% of the total flow of the river. Thus, it is not strange to find considerably high levels of organic contaminants along the river and increasing concentrations when moving downstream due to the also increasing number of WWTPs and population pressure. Besides conventional contaminants such as pesticides, Hg, organochlorine compounds, polycyclic aromatic hydrocarbons (PAHs), alkylphenols and polybrominated diphenyl ethers (PBDEs), emerging contaminants such as pharmaceuticals and personal care products and illicit drugs represent an overgrowing portion of trace organic contaminants of concern in two studied Iberian rivers (Ebro and Llobregat). This presentation summarizes the findings of several studies and monitoring programs conducted with the aim of getting a better insight about the sources and fate of pesticides, pharmaceuticals, illicit drugs and personal care products in the aquatic environment in Spain. The occurrence of these contaminants is discussed in relationship to their removal in WWTPs, influence of hydrological conditions in the receiving river waters, sediments and dilution factors. The removal of some of them (e.g., acetaminophen, diclofenac, ibuprofen, carbamazepine and atenolol as well as the illicit drugs cocaine and methadone) with advanced water treatments and the study ofthe formed transformation products and their toxicity is also presented. In addition, the risk posed by these emerging contaminants in both surface and effluent wastewaters was assessed towards different aquatic organisms (algae, daphnids and fish) by determining hazard indexes.These indexes are further correlated with some biological descriptors characterizing both the structure and functioning of the receiving aquatic ecosystems such as biofilms or the macroinvertebrate community. The study completes with an analysis of the strategies under discussion within the European Countries in order to reduce the environmental risk posed by the occurrence of the most critical emerging contaminants in surface waters. In particular the recent European directive 2013/39/UE as regards priority substances in the field of water policy and the Swiss Micropoll Strategy are presented and their main issues discussed in terms of relevant compounds to monitor regularly, priority actions to reduce their occurrence, best techniques to adopt in upgrading existing wastewater treatment plants

Halogenated and organophosphorus flame retardants in European aquaculture samples

This work monitors flame retardants in sediment, mussel and water samples from European fish farms. Polybrominated diphenyl ethers (PBDEs) were detected in 95% of the sediment and mussel samples with mean levels of 8.60 ± 22.6 ng g−1 dw in sediments and 0.07 ± 0.18 ng g−1 dw in mussels. BDE-209 was the main contributor for the sediments and BDE-47 was found in about 60% of the samples of both matrices. Pentabromoethylbenzene (PBEB) and hexabromobenzene (HBB) were detected in 42% of the sediments, but not in mussels. Decabromodiphenyl ethane (DBDPE) was found in about 55% of the samples of both matrices. The same happened for dechloranes in mussels, but they were detected in 92% of the sediments. Syn-DP and anti-DP were always the main contributors. Methoxylated PBDEs (MeO-PBDEs) were detected in all mussels and some sediments, mainly 6-MeO-BDE-47 and 2′-MeO-BDE-68. Organophosphorus flame retardants (OPFRs) were found in all matrices with concentrations of 0.04–92.8 ng g−1 dw in sediment, 0.50–102 ng g−1 dw in mussel and 0.43–867 ng l−1 in water. Only OPFRs were analysed in water samples as halogenated flame retardants and MeO-PBDEs are highly unlikely to be detected in water due to their physicochemical properties. Flame retardants have no application in fish farming so results should reflect the impact of human activity on the farm locations. A large majority of the most contaminated samples were collected from sampling spots that were at urban shores or in enclosed water bodies not completely open to the sea