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ABSTRACT: Due to the increasing production of nanoparticles (NPs) and their potential release in the aquatic environment, evaluation of their biological impact on aquatic organisms represents a major concern. Suspension feeding invertebrates, in particular bivalve mollusks, may play a role in NP biotransformation and transfer through food webs and may represent a significant target for NP toxicity. In this work, the in vivo effects of titanium dioxide (n-TiO(2)), one of the most widespread NPs in use, were investigated in the bivalve Mytilus galloprovincialis, largely utilised as a sentinel for marine contamination. Mussels were exposed for 96h to different concentrations of n-TiO(2) suspensions (1, 10 and 100μgL(-1)) and multiple responses were evaluated in the digestive gland and immune cells, the haemocytes. In the digestive gland, n-TiO(2) affected lysosomal and oxidative stress biomarkers and decreased transcription of antioxidant and immune-related genes. In the haemocytes, n-TiO(2) decreased lysosomal membrane stability-LMS and phagocytosis, increased oxyradical production and transcription of antimicrobial peptides; moreover, pre-apoptotic processes were observed. The effects of n-TiO(2) on digestive gland and haemocytes were distinct, also depending on the endpoint and on nominal NP concentrations, with many significant responses elicited by the lowest concentrations tested. The results show that n-TiO(2), at concentrations close to predicted environmental levels, significantly affected different functional and molecular parameters of mussel digestive gland and immune cells. In particular, the observed changes in immune parameters that represent significant biomarkers of exposure at the organism level suggest that exposure to n-TiO(2) may pose a serious risk to mussel health.
Aquatic toxicology (Amsterdam, Netherlands) 02/2013; 132-133C:9-18. · 3.12 Impact Factor
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ABSTRACT: Abstract Substantial limitations and uncertainties hinder the exposure assessment of engineered nanomaterials (ENMs). The present deficit of reliable measurements and models will inevitably lead in the near term to qualitative and uncertain exposure estimations, which may fail to support adequate risk assessment and management. Therefore it is necessary to complement the current toolset with user-friendly methods for near-term nanosafety evaluation. This paper proposes an approach for relative exposure screening of ENMs. For the first time, an exposure model explicitly implements quantitative weight of evidence (WoE) methods and utilizes expert judgment for filling data gaps in the available evidence-base. Application of the framework is illustrated for screening of exposure scenarios for nanoscale titanium dioxide, carbon nanotubes and fullerenes, but it is applicable to other nanomaterials as well. The results show that the WoE-based model overestimates exposure for scenarios where expert judgment was substantially used to fill data gaps, which suggests its conservative nature. In order to test how variations in input data influence the obtained results, probabilistic Monte Carlo sensitivity analysis was applied to demonstrate that the model performs in stable manner.
Nanotoxicology 12/2012; · 5.76 Impact Factor
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ABSTRACT: Abstract Hazard identification is an important step in assessing nanomaterial risk and is required under multiple regulatory frameworks in the US, Europe and worldwide. Given the emerging nature of the field and complexity of nanomaterials, multiple studies on even basic material properties often result in varying data pointing in different directions when data interpretation is attempted. Weight of Evidence (WOE) evaluation has been recommended for nanomaterial risk assessment, but the majority of WOE frameworks are qualitative in nature and do not satisfy the growing needs for objectivity and transparency that are necessary for regulatory decision making. This paper implements a quantitative WOE framework that utilizes Multi-Criteria Decision Analysis methodology for integrating individual studies on nanomaterial hazard resulting from physico-chemical and toxicological properties of nanomaterials. For the first time, a WOE approach explicitly integrates expert evaluation of data quality of available information. Application of the framework is illustrated for titanium dioxide nanoparticles (nano-TiO2), but the approach is designed to compare the relative hazard of several nanomaterials as well as emerging stressors in general.
Nanotoxicology 11/2012; · 5.76 Impact Factor
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Helinor Johnston,
Giulio Pojana,
Stefano Zuin,
Nicklas Raun Jacobsen,
Peter Møller,
Steffen Loft,
Manuela Semmler-Behnke,
Catherine McGuiness,
Dominique Balharry, Antonio Marcomini,
Håkan Wallin,
Wolfgang Kreyling,
Ken Donaldson,
Lang Tran,
Vicki Stone
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ABSTRACT: PARTICLE_RISK was one of the first multidisciplinary projects funded by the European Commission's Framework Programme that was responsible for evaluating the implications of nanomaterial (NM) exposure on human health. This project was the basis for this review which identifies the challenges that exist within the assessment of NM risk. We have retrospectively reflected on the findings of completed nanotoxicology studies to consider what progress and advances have been made within the risk assessment of NMs, as well as discussing the direction that nanotoxicology research is taking and identifying the limitations and failings of existing research. We have reflected on what commonly encountered challenges exist and explored how these issues may be resolved. In particular, the following is discussed (i) NM selection (ii) NM physico-chemical characterisation; (iii) NM dispersion; (iv) selection of relevant doses and concentrations; (v) identification of relevant models, target sites and endpoints; (vi) development of alternatives to animal testing; and (vii) NM risk assessment. These knowledge gaps are relatively well recognised by the scientific community and recommendations as to how they may be overcome in the future are provided. It is hoped that this will help develop better defined hypothesis driven research in the future that will enable comprehensive risk assessments to be conducted for NMs. Importantly, the nanotoxicology community has responded and adapted to advances in knowledge over recent years to improve the approaches used to assess NM hazard, exposure and risk. It is vital to learn from existing information provided by ongoing or completed studies to avoid unnecessary duplication of effort, and to offer guidance on aspects of the experimental design that should be carefully considered prior to the start of a new study.
Critical Reviews in Toxicology 11/2012; · 5.16 Impact Factor
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ABSTRACT: Large scale (e.g. regional or national) assessments of contaminated sites may be very costly in terms of investigation and methodological (i.e. risk assessment procedures) requirements and may produce a quantity of information that usually discourages examination by decision-makers. Moreover, most of the existing tools effectively support local environmental risk assessment and management, but lack the capabilities of larger scale analysis, not mentioning the absence of the relevant component of socio-economic prioritization. To respond to the concerns and the management needs of experts and decision makers, the Spatial decision support sYstem for Regional rIsk Assessment of Degraded land (SYRIADE DSS) was developed and is presented according to its three modules: Regional Risk Assessment, Socio-economic Assessment and Integrated Assessment, respectively. The system allows to rank potentially contaminated sites for priority of investigation, when no information on characterization and risk by site specific methodologies is available. This GIS-based system embeds an innovative spatial and relative risk assessment procedure, and proposes the integrated analysis of different data (environmental and socio-economic) for the concerned sites, eliciting when necessary experts' knowledge and stakeholders' values (through Multi Criteria Decision Analysis, MCDA, methodologies). The application to a Polish case-study shows the performance and the flexibility of the system in investigating and mapping (potentially) contaminated sites at the regional scale.
Environment international 08/2012; 48:121-32. · 4.79 Impact Factor
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ABSTRACT: The recent definition and submission of WFD-compliant River Basin Management Plans required large efforts of water managers and highlighted a number of data, knowledge and methodological gaps that need to be fulfilled during the next management cycle. The complexity of the WFD implementation process calls for easy-to-use, reliable and scientifically sound decision support tools that consider relevant aspects of the basin of concern. For this purpose, a Decision Support System (DSS) for risk-based assessment and management of river basins was developed within the EU MODELKEY project. The MODELKEY DSS allows assessing the chemical and ecological status of water bodies by applying both the One-Out All-Out principle, suggested by the WFD, and a novel Integrated Risk Assessment (IRA) methodology, developed within the project. In this paper, main results obtained by DSS application to two large European rivers, i.e. Elbe and Danube, are presented and discussed, based on a set of biological, chemical and physico-chemical indicators, which have been evaluated in relation to available reference conditions. The WFD ecological and chemical status assessment as well as analysis of intermediate results was strongly affected by the methods used to derive reference conditions, the applied indicators, and the methods used to aggregate indicators results. Minimally disturbed conditions (MDC) are the best choice as reference conditions, being characterized by generally high index values (good status) for all biological indices. Where MDC are not available, historical conditions could be a good substitute; they should be preferred to least disturbed sites (in particular when the river is generally impaired as the Danube River).
River Systems. 03/2012; 20(1-2):23-40.
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ABSTRACT: Climate forcing is forecasted to influence the Adriatic Sea region in a variety of ways, including increasing temperature, and affecting wind speeds, marine currents, precipitation and water salinity. The Adriatic Sea is intensively developed with agriculture, industry, and port activities that introduce pollutants to the environment. Here, we developed and applied a Level III fugacity model for the Adriatic Sea to estimate the current mass balance of polychlorinated biphenyls in the Sea, and to examine the effects of a climate change scenario on the distribution of these pollutants. The model's performance was evaluated for three PCB congeners against measured concentrations in the region using environmental parameters estimated from the 20th century climate scenario described in the Special Report on Emission Scenarios (SRES) by the IPCC, and using Monte Carlo uncertainty analysis. We find that modeled fugacities of PCBs in air, water and sediment of the Adriatic are in good agreement with observations. The model indicates that PCBs in the Adriatic Sea are closely coupled with the atmosphere, which acts as a net source to the water column. We used model experiments to assess the influence of changes in temperature, wind speed, precipitation, marine currents, particulate organic carbon and air inflow concentrations forecast in the IPCC A1B climate change scenario on the mass balance of PCBs in the Sea. Assuming an identical PCBs' emission profile (e.g. use pattern, treatment/disposal of stockpiles, mode of entry), modeled fugacities of PCBs in the Adriatic Sea under the A1B climate scenario are higher because higher temperatures reduce the fugacity capacity of air, water and sediments, and because diffusive sources to the air are stronger.
Chemosphere 03/2012; 87(9):1045-51. · 3.21 Impact Factor
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ABSTRACT: The published results on nanoparticles cytotoxicity and genotoxicity such as titanium dioxide nanoparticles (TiO(2) NPs) are inconsistent, and often conflicting and insufficient. Since different parameters may have impact on the toxicity results, there is need to lay stress on detailed characterization of NPs and the use of different testing conditions for assessment of NPs toxicity. In order to investigate whether dispersion procedures influence NP cytotoxicity and genotoxicity, we compared two protocols giving TiO(2) NP dispersions with different stability and agglomeration states. Detailed primary and secondary characteristics of both TiO(2) NP dispersions in culture media were carried out before toxicological testing; TK6 human lymphoblast cells, EUE human embryonic epithelial cells and Cos-1 monkey kidney fibroblasts were used to assess cytotoxicity (by trypan blue exclusion, proliferation activity and plating efficiency assays) and genotoxicity (by the comet assay). DNA strand breaks were detected by the alkaline comet assay. DNA oxidation lesions (especially 8-oxo-7,8-dihydroguanine, 8-oxoG) were measured with a modified comet assay including incubation with specific repair enzyme formamidopyrimidine DNA glycosylase (FPG). The TiO(2) NPs dispersion with large agglomerates (3 min sonication and no serum in stock solution) induced DNA damage in all three cell lines, while the TiO(2) NPs dispersed with agglomerates less than 200 nm (foetal serum in stock solution and sonication 15 min) had no effect on genotoxicity. An increased level of DNA oxidation lesions detected in Cos-1 and TK6 cells indicates that the leading mechanism by which TiO(2) NPs trigger genotoxicity is most likely oxidative stress. Our results show that the dispersion method used can influence the results of toxicity studies. Therefore at least two different dispersion procedures should be incorporated into assessment of cyto- and genotoxic effects of NPs. It is important, when assessing the hazard associated with NPs, to establish standard testing procedures and thorough strategies to consider the diverse conditions relevant to possible exposures.
Journal of Environmental Monitoring 02/2012; 14(2):455-64. · 1.99 Impact Factor
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Ali Kermanizadeh,
Giulio Pojana,
Birgit K Gaiser,
Renie Birkedal,
Dagmar Bilaničová,
Håkan Wallin,
Keld Alstrup Jensen,
Börje Sellergren,
Gary R Hutchison, Antonio Marcomini,
Vicki Stone
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ABSTRACT: Abstract Effects on the liver C3A cell line treated with a panel of engineered nanomaterials (NMs) consisting of two zinc oxide particles (ZnO; coated 100 nm and uncoated 130 nm), two multi-walled carbon nanotubes (MWCNTs), one silver (Ag < 20 nm), one 7 nm anatase, two rutile TiO2 nanoparticles (10 and 94 nm) and two derivatives with positive and negative covalent functionalisation of the 10 nm rutile were evaluated. The silver particles elicited the greatest level of cytotoxicity (24 h LC50 – 2 µg/cm2). The silver was followed by the uncoated ZnO (24 h LC50 – 7.5 µg/cm2) and coated ZnO (24 h LC50 – 15 µg/cm2) particles with respect to cytotoxicity. The ZnO NMs were found to be about 50–60% soluble which could account for their toxicity. By contrast, the Ag was <1% soluble. The LC50 was not attained in the presence of any of the other engineered NMs (up to 80 µg/cm2). All NMs significantly increased IL-8 production. Meanwhile, no significant change in TNF-α, IL-6 or CRP was detected. Urea and albumin production were measured as indicators of hepatic function. These markers were only altered by the coated and uncoated ZnO, which significantly decreased albumin production.
Nanotoxicology 01/2012; · 5.76 Impact Factor
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ABSTRACT: Abstract It has been largely recognised that substantial limitations and uncertainties make the conventional risk assessment (RA) of chemicals unfeasible to apply to engineered nanomaterials (ENMs) today, which leaves the regulators with little support in the near term. The aim of this paper is to discuss the state of the art in the area of the RA of nanomaterials, focusing on the available data and approaches. There is a paucity of reliable information in the online safety databases and the literature is dominated by (eco)toxicity studies, while the nano-exposure research lags behind. Most of the reviewed nano-RA approaches are designed to serve as preliminary risk screening and/or research prioritisation tools and are not intended to support regulatory decision making. In this context, we recommend to further study the possibilities to apply complementary/alternative tools for near-term RA of ENMs in order to facilitate their timely regulation, using the data that are currently available in the literature.
Nanotoxicology 01/2012; · 5.76 Impact Factor
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ABSTRACT: The potential toxicity of engineered nanoparticles (NPs) for humans and the environment represents an emerging issue. Since the aquatic environment represents the ultimate sink for NP deposition, the development of suitable assays is needed to evaluate the potential impact of NPs on aquatic biota. The immune system is a sensitive target for NPs, and conservation of innate immunity represents an useful basis for studying common biological responses to NPs. Suspension-feeding invertebrates, such as bivalves, are particularly at risk to NP exposure, since they have extremely developed systems for uptake of nano and microscale particles integral to intracellular digestion and cellular immunity. Evaluation of the effects of NPs on functional parameters of bivalve immunocytes, the hemocytes, may help understanding the major toxic mechanisms and modes of actions that could be relevant for different NP types in aquatic organisms.In this work, a battery of assays was applied to the hemocytes of the marine bivalve Mytilus galloprovincialis to compare the in vitro effects of different n-oxides (n-TiO(2), n-SiO(2), n-ZnO, n-CeO(2)) chosen on the basis of their commercial and environmental relevance. Physico-chemical characterization of both primary particles and NP suspensions in artificial sea water-ASW was performed. Hemocyte lysosomal and mitochondrial parameters, oxyradical and nitric oxide production, phagocytic activity, as well as NP uptake, were evaluated. The results show that different n-oxides rapidly elicited differential responses hemocytes in relation to their chemical properties, concentration, behavior in sea water, and interactions with subcellular compartments. These represent the most extensive data so far available on the effects of NPs in the cells of aquatic organisms. The results indicate that Mytilus hemocytes can be utilized as a suitable model for screening the potential effects of NPs in the cells of aquatic invertebrates, and may provide a basis for future experimental work for designing environmentally safer nanomaterials.
PLoS ONE 01/2012; 7(5):e36937. · 4.09 Impact Factor
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ABSTRACT: In this work in situ proliferation of A549 human lung epithelial carcinoma cells exposed to nanomaterials (NMs) was investigated in the presence or absence of 10% serum. NMs were selected based on chemical composition, size, charge and shape (Lys-SiO(2), TiO(2), ZnO, and multi walled carbon nanotubes, MWCNTs). Cells were treated with NMs and 4h later, cytochalasin-B was added. 36 h later, cell morphology was analyzed under a light microscope. Nuclearity was scored to determine the cytokinesis-block proliferation index (CBPI). CBPI, based on percentage of mono-, bi- and multi-nucleated cells, reflects cell toxicity and cell cycle delay. For some conditions depending on NM type (TiO(2) and MWCNT) and serum concentration (0%) scoring of CBPI was impossible due to overload of agglomerated NMs. Moreover, where heavy agglomeration occurs, micronuclei (MN) detection and scoring under microscope was prevented. A statistically significant decrease of CBPI was found for ZnO NM suspended in medium in the absence or presence of 10% serum at 25 μg/ml and 50 μg/ml, respectively and for Lys-SiO(2) NM at 3.5 μg/ml in 0% serum. Increase in MN frequency was observed in cells treated in 10% serum with 50 μg/ml ZnO. In 0% serum, the concentrations tested led to high toxicity. No genotoxic effects were induced by Lys-SiO(2) both in the absence or presence of serum up to 5 μg/ml. No toxicity was detected for TiO(2) and MWCNTs in both 10% and 0% serum, up to the dose of 250 μg/ml. Restoration of CBPI comparable to untreated control was shown for cells cultured without serum and treated with 5 μg/ml of Lys-SiO(2) NM pre-incubated in 100% serum. This observation confirms the protective effect of serum on Lys-SiO(2) NM cell toxicity. In conclusion in situ CBPI is proposed as a simple preliminary assay to assess both NMs induced cell toxicity and feasibility of MN scoring under microscope.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 10/2011; 745(1-2):21-7. · 2.85 Impact Factor
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ABSTRACT: In assessing hazard for human health posed by newly engineered nanomaterials (ENM), approaches such as Weight of Evidence (WOE) and expert judgment are required to develop conclusions about the hazard of ENM. This is because all factors affecting hazard are not currently well defined and are often subject to different interpretation. Here we report the application of a WOE procedure to assess the potential of ENM to cause harm for human health, by integrating and combining physicochemical properties of NM and toxicity data obtained within the EU-funded Particle Risk project. The procedure was applied to carbon black (CB), single-walled carbon nanotubes (SWNT), C60 fullerene and quantum dots (QD) ENM tested during the Particle Risk project. The results show that some of the investigated ENM present a relatively higher hazardousness level on the basis of the integration of their physicochemical properties and toxicological effects, and that their hazard may be ranked as follow: QD > C60 > SWNT > CB. This case study shows the utility of WOE approach to obtain a hazard ranking of ENM.
Nanotoxicology 09/2011; 5(3):445-58. · 5.76 Impact Factor
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ABSTRACT: Due to the continuous development and production of manufactured nanomaterials or nanoparticles (NPs), their uptake and effects in the aquatic biota represent a major concern. Estuarine and coastal environments are expected to represent the ultimate sink for NPs, where their chemical behavior (aggregation/agglomeration) and consequent fate may be critical in determining the biological impact. Bivalve mollusks are abundant from freshwater to marine ecosystems, where they are widely utilized in biomonitoring of environmental perturbations. As suspension-feeders, they have highly developed processes for cellular internalization of nano- and micro-scale particles (endo- and phagocytosis), integral to key physiological functions such as intra-cellular digestion and cellular immunity. Here we will summarise available information on the effects of different types of NPs in different bivalve species, in particular Mytilus spp. Data on the effects and modes of action of different NPs on mussel hemocytes in vitro demonstrate that cell-mediated immunity represents a significant target for NPs. Moreover, in vivo exposure to NPs indicates that, due to the physiological mechanisms involved in the feeding process, NP agglomerates/aggregates taken up by the gills are directed to the digestive gland, where intra-cellular uptake of nanosized materials induces lysosomal perturbations and oxidative stress. Overall, bivalves represent a particularly suitable model for investigating the effects and mechanisms of action underlying the potential toxicity of NPs in marine invertebrates.
Marine environmental research 06/2011; 76:16-21. · 1.76 Impact Factor
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ABSTRACT: Environmental risks are traditionally assessed and presented in non spatial ways although the heterogeneity of the contaminants spatial distributions, the spatial positions and relations between receptors and stressors, as well as the spatial distribution of the variables involved in the risk assessment, strongly influence exposure estimations and hence risks. Taking into account spatial variability is increasingly being recognized as a further and essential step in sound exposure and risk assessment. To address this issue an innovative methodology which integrates spatial analysis and a relative risk approach was developed. The purpose of this methodology is to prioritize sites at regional scale where a preliminary site investigation may be required. The methodology aimed at supporting the inventory of contaminated sites was implemented within the spatial decision support sYstem for Regional rIsk Assessment of DEgraded land, SYRIADE, and was applied to the case-study of the Upper Silesia region (Poland). The developed methodology and tool are both flexible and easy to adapt to different regional contexts, allowing the user to introduce the regional relevant parameters identified on the basis of user expertise and regional data availability. Moreover, the used GIS functionalities, integrated with mathematical approaches, allow to take into consideration, all at once, the multiplicity of sources and impacted receptors within the region of concern, to assess the risks posed by all contaminated sites in the region and, finally, to provide a risk-based ranking of the potentially contaminated sites.
Environment international 06/2011; 37(8):1307-20. · 4.79 Impact Factor
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ABSTRACT: The occurrence and seasonal distribution of 14 pharmaceutical substances of different classes were investigated in two drinking water treatment plants (DWTPs) supplied by the two main Italian rivers, the Po and the Adige (Northern Italy). The therapeutic categories of the selected pharmaceuticals included anti-inflammatory drugs, β-blockers, lipid regulators, diuretics, anti-epileptics, antibiotics and a steroidal hormone. The named compounds were assessed in samples collected from the river water inlet and after each purification stage (sand filtration, ozone treatment, granular active carbon (GAC)). Six of the 14 selected pharmaceuticals were found in all analysed samples, with concentration levels ranging from 1 ng l−1 for atorvastatin to 69 ng l−1 for atenolol in the drinking water produced. The granular active carbon stage resulted the most efficient in eliminating the examined chemicals from the water (removal range: 12–95%, average: 68%), while the sand filtration stage resulted the least effective treatment (removal range: 4–37%, average: 13%). The observed differences between winter and summer conditions, in terms of residual concentrations and number of detected analytes, seemed to depend mainly on the quality of the river water supplies. To the best of our knowledge, these are the first reported data on the presence of pharmaceuticals in drinking water obtained from the water treatment of these two rivers.
Intern. J. Environ. Anal. Chem. 05/2011; 91(6):537-552.
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Michaela Hein,
Eric de Deckere,
Dick de Zwart,
Edwin M. Foekema, Antonio Marcomini,
Isabel Muñoz,
Leo Posthuma,
Stefanie Rotter,
Sergi Sabater,
Claudia Schmitt,
Mechthild Schmitt-Jansen,
Helmut Segner,
Elena Semenzin,
Jos van Gils,
Bert van Hattum,
L. Alexander van Vliet,
Peter C. von der Ohe,
Werner Brack
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ABSTRACT: The EU Water Framework Directive (WFD) requires the achievement of good ecological and chemical
status in European river basins. However, evidence is increasing that a majority of European water bodies will not achieve this goal. Nutrient emissions and related eutrophication together with hydromorphological alterations have been suggested as the major driving forces of this insufficient
ecological status. MODELKEY (511237 GOCE, FP6) provides strong evidence that toxic chemicals also affect the ecological status of European rivers. This was demonstrated in the case study rivers Elbe, Scheldt and Llobregat on different scales. This paper summarises key findings of MODELKEY including recommendations for WFD implementation. We
• provide evidence of toxic stress in aquatic ecosystems,
• provide evidence that impairment of ecological status results from impact of multiple stressors,
• suggest a tiered approach to assess impact of chemicals on ecological status,
• suggest a new approach for deriving candidate compounds for monitoring and prioritisation,
• call for consideration of bioavailability and bioaccumulation in chemical status assessments,
• suggest improvements for WFD water quality monitoring programmes,
• provide new integrated tools for basin-scale risk assessment and decision making,
• developed a Decision Support System to support river basin management.
These key results will be presented in a series of ten integrated sections; for the scientific details please refer to publications listed on the MODELKEY website (http:// www.modelkey.org/). This article also looks beyond MODELKEY and proposes a combination of MODELKEY diagnostic tools with recent ecological methods to further improve effectiveness of river basin management.
Umweltwissenschaften und Schadstoff-Forschung 04/2010; 22:217.228.
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ABSTRACT: The occurrence and behavior of the aromatic surfactants linear alkylbenzene sulphonates (LAS) andnonylphenol polyethoxylates (NPE) as well as their biotransformation products in the central lagoon of Venice, Italy, were investigated by monitoring deep- and shallow-water lagoon stations, two riverine sites, and one sea station. Additional samplings were conducted at the three inlets connecting the lagoon with the open sea under both ebb and low-tide conditions, and a radiometrically dated sediment core spanning the last century was examined. The spatial distributions of LAS, NPE, and their carboxylic metabolites sulphophenyl carboxylates and nonylphenol carboxylates, respectively, appeared to be rather homogeneous over the entire central lagoon. Remarkable seasonal differences were found, however, primarily because of the increased biodegradation at temperatures greater than 20°C. The estimated primary and ultimate biodegradations of LAS in the lagoon waters were approximately 90 and 72%, respectively. Analysis of the dated sediment core showed similar annual fluxes of both LAS and NPE (48 ng/cm2 year), which were between previously reported values of polychlorinated biphenyls (4.7 ng/cm2 year) and polycyclic aromatic hydrocarbons (167 ng/cm2 year).
Environmental Toxicology and Chemistry 11/2009; 19(8):2000 - 2007. · 2.81 Impact Factor
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ABSTRACT: As the nanotechnology industries increase production, nanoscale products will enter the aquatic environment, posing a possible threat to aquatic organisms. Suspension-feeding invertebrates may represent a unique target group for nanoparticle (NP) ecotoxicity, since they have highly developed processes for the cellular internalisation of nano- and microscale particles (endocytosis and phagocytosis), which are integral to key physiological functions such as intracellular digestion and cellular immunity. In the marine bivalve Mytilus, short-term exposure to nanosized carbon black (NCB) was shown to significantly affect immune parameters of immune cells, the hemocytes, in vitro. In this work, we further investigated the effects of other types of commercial NPs (C60 fullerene, TiO(2) and SiO(2) at 1, 5, 10 microg/ml) on Mytilus hemocytes. Characterization of NP suspensions in artificial sea water (ASW) was performed, indicating the formation of agglomerates of different sizes for different types of NPs. None of the NP tested significantly affected lysosomal membrane stability, indicating the lack of a major toxic effect. However, all NP suspensions induced a concentration-dependent lysozyme release, extracellular oxyradical and nitric oxide (NO) production, to a different extent and with different time courses depending on the concentration and the NP type. The inflammatory effects of NPs were mediated by rapid activation of the stress-activated p38 MAPK. The results further support the hypothesis that in bivalves the immune system represents a significant target for NPs.
Aquatic toxicology (Amsterdam, Netherlands) 10/2009; 96(2):151-8. · 3.12 Impact Factor
