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Using multiple indices to evaluate scenarios for the remediation of contaminated land: the Porto Marghera (Venice, Italy) contaminated site Full text
2009
Critto, Andrea | Agostini, Paola
Background, aim, and scope The management of contaminated sites requires the investigation of different involved aspects (from socioeconomic to risk and technological issues) and the presentation of useful and condensed information to decision makers. For this purpose, indices are more and more recognized as effective and valuable tools. This paper presents specific indices created within the DEcision Support sYstem for REhabilitation of contaminated sites (DESYRE). Materials and methods DESYRE is a software which aids decision making for the rehabilitation of a large contaminated site (i.e., megasite) by the creation and comparison of different rehabilitation alternatives. The software is composed of six modules, each dealing with a specific aspect of the remediation process, ending with the decision module. In this module, scenarios (i.e., suitable solutions for the rehabilitation of the contaminated site including selected land use, socioeconomic benefits, remediation costs, time span, environmental impacts, technology set/s, and residual risk) are created and evaluated by means of suitable indices. Nine indices cover the socioeconomic, risk, technological, cost, time, and environmental impact aspects. Mathematical algorithms are used to calculate these indices by taking into account data collected during the analytical steps of the DESYRE system and elaborated through the support of the spatial analysis, which is embedded in the system. Results The case study of Porto Marghera, Venice, Italy is presented in order to document the effectiveness of developed indices in evaluating management solutions and presenting options to decision makers. For the purpose of this study, three different scenarios for the remediation of a part of the site of Porto Marghera (approximately 530 ha) are developed and compared. The three scenarios consider the industrial land use and deal with the contamination in soil caused by inorganic and organic compounds. The scenarios mainly differ for the number of the included remediation technologies and for the spatial distribution of the technologies on the considered area. Discussion Indices results allow the user to more easily evaluate the advantages and limits of each scenario in order to select the most appropriate one. For instance, the risk indices allow the user to identify scenarios with good performance in reducing the extension of risk areas and the risk magnitude. Equally, the technological indices support the achievement of efficient remedial solutions characterized by a limited number of technologies, applied to extended areas and with high performance. The environmental impact index allows users to estimate the wider effects on the environment of the selected solutions, while the socioeconomic index is the result of social and economic investigations of the regional and local conditions, which ends with the identification of the best land use (e.g., the industrial one for the Porto Marghera area). Conclusions The proposed nine DESYRE indices provide more complete information to investigate suitable management solutions. DESYRE indices facilitate the definition of a consensus among stakeholders and the achievement of a widely shared solution for contaminated site management, even at larger sites, such as Porto Marghera. Recommendations and perspectives Further improvements to the system may be adopted, e.g., the possibility to aggregate results of the different assessments into one synthetic index per scenario or the inclusion of a Group Decision Making procedure.
Show more [+] Less [-]The Cl-initiated oxidation of CH₃C(O)OCH=CH₂, CH₃C(O)OCH₂CH=CH₂, and CH₂=CHC(O)O(CH₂)₃CH₃ in the troposphere Full text
2009
Blanco, María B. | Bejan, Iustinian | Barnes, Ian | Wiesen, Peter | Teruel, Mariano A.
Background, aim, and scope Unsaturated esters are emitted to the atmosphere from biogenic and anthropogenic sources, including those from the polymer industry. Little information exists concerning the atmospheric degradation of unsaturated esters, which are mainly initiated by OH radicals. Limited information is available on the degradation of alkenes by Cl atoms and almost no data exists for the reactions of unsaturated esters with Cl atoms. This data is necessary to assess the impact of such reactions in maritime environments where, under circumstances, OH radical- and Cl atom-initiated oxidation of the compounds can be important. Rate coefficients for the reactions of chlorine atoms with vinyl acetate, allyl acetate, and n-butyl acrylate have been determined at 298 ± 3 K and atmospheric pressure. The kinetic data have been used in combination with that for structurally similar compounds to infer the kinetic contributions from the possible reaction channels to the overall reaction rate. Materials and methods The decay of the organics was followed using in situ Fourier transform infrared spectroscopy and the rate coefficients were determined using a relative kinetic method and different hydrocarbon reference compounds. Results The following room temperature rate coefficients (in cm³ molecule⁻¹ s⁻¹) were obtained: k ₁ (Cl + CH₃C(O)OCH=CH₂) = (2.68 ± 0.91) x 10⁻¹⁰, k ₂ (Cl + CH₃C(O)OCH₂CH=CH₂) = (1.30 ± 0.45) x 10⁻¹⁰, and k ₃ (Cl + CH₂=CHC(O)O(CH₂)₃CH₃) = (2.50 ± 0.78) x 10⁻¹⁰, where the uncertainties are a combination of the 2σ statistical errors from linear regression analyses and a contribution to cover uncertainties in the rate coefficients of the reference hydrocarbons. Discussion This is the first kinetic study of the title reactions under atmospheric conditions. The kinetic data were analyzed in terms of reactivity trends and used to estimate the atmospheric lifetimes of the esters and assess their potential importance in the marine atmosphere. Conclusions Although reaction with OH radicals is the major atmospheric sink for the unsaturated esters studied, reaction with Cl atoms can compete in the early morning hours in coastal areas where the Cl concentration can reach peak values as high as 1 x 10⁵ atoms cm⁻³. The calculated residence times show that the chemistry of unsaturated esters will impact air quality locally near their emission sources. Recommendations and perspectives The reactions need to be studied over the range of temperatures and pressures generally encountered in the marine atmosphere. In addition, product studies should also be performed as a function of temperature since this will allow degradation mechanisms to be derived, which are representative for the wide range of conditions occurring in marine environments. Inclusion of the kinetic and product data in tropospheric numerical models will allow an assessment of potential environmental impacts of the esters for different marine pollution scenarios.
Show more [+] Less [-]Temporal concentration changes of DEET, TCEP, terbutryn, and nonylphenols in freshwater streams of Hesse, Germany: possible influence of mandatory regulations and voluntary environmental agreements Full text
2009
Quednow, Kristin | Püttmann, Wilhelm
Background, aim, and scope The present study focuses on the temporal concentration changes of four common organic pollutants in small freshwater streams of Hesse, Germany. The substances (tris(2-chloroethyl)phosphate (TCEP), the technical isomer mixture of 4-nonylphenol (NP), 2-(t-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine (terbutryn), and N,N-diethyl-m-toluamide (DEET)) are subject to differing regulations. Whereas the use of NP and the related nonylphenolethoxylates (NPEOs) are almost completely banned under EU directive 2003/53/EC, the herbicide terbutryn is only restricted for use as a herbicide in the majority of member states of the European Union (EU). In contrast, TCEP and DEET are not regulated by legislation, but have been replaced in some products through consumer pressure. The impact of regulation on the environmental concentrations of these pollutants is discussed. Materials and methods The substances were monitored in small freshwater streams in the Hessisches Ried region, Germany, during the period September 2003 to September 2006. The samples were extracted with solid phase extraction (SPE) and analyzed by coupled gas chromatography-mass spectrometry (GC-MS). Results All target compounds were detected frequently within the fresh water streams of the study area. Monitoring in the study area revealed a significant concentration decrease only for NP. For the other three compounds, no significant concentration decrease was observed. Terbutryn concentrations and loads showed a seasonal trend with higher levels in summer and autumn, but were also present in winter and spring. Concentrations of TCEP and DEET were in the range of prior investigations. Discussion The decrease of NP concentrations and loads during the sampling period indicates that the regulation of NP and NP ethoxylates has led to a significant improvement in reducing the occurrence of this compound in the aquatic environment. Furthermore, the ban on agricultural use of terbutryn at the end of 2003 had no discernable influence on terbutryn concentrations in the following years. Conclusions The benefits of national bans or self-regulations by manufacturers on several chemicals appear to be limited. In contrast, the European-wide ban (of NP) revealed to be effective in preventing the substance from entering the aquatic environment on a large scale and reduced the NP concentration to an acceptable level (i.e., below the PNEC). Recommendations and perspectives Further research is needed to investigate diffuse sources and point sources of terbutryn not related to agriculture. Further research is required to find an explanation for the ongoing high concentration of TCEP in river water despite of the supposed replacement of TCEP by TCPP already in the 1990s.
Show more [+] Less [-]Chemical transport models Full text
2009
Mihailovic, Dragutin T | Alapaty, Kiran | Podrascanin, Zorica
Background, aim, and scope Improving the parameterization of processes in the atmospheric boundary layer (ABL) and surface layer, in air quality and chemical transport models. To do so, an asymmetrical, convective, non-local scheme, with varying upward mixing rates is combined with the non-local, turbulent, kinetic energy scheme for vertical diffusion (COM). For designing it, a function depending on the dimensionless height to the power four in the ABL is suggested, which is empirically derived. Also, we suggested a new method for calculating the in-canopy resistance for dry deposition over a vegetated surface. Materials and methods The upward mixing rate forming the surface layer is parameterized using the sensible heat flux and the friction and convective velocities. Upward mixing rates varying with height are scaled with an amount of turbulent kinetic energy in layer, while the downward mixing rates are derived from mass conservation. The vertical eddy diffusivity is parameterized using the mean turbulent velocity scale that is obtained by the vertical integration within the ABL. In-canopy resistance is calculated by integration of inverse turbulent transfer coefficient inside the canopy from the effective ground roughness length to the canopy source height and, further, from its the canopy height. Results This combination of schemes provides a less rapid mass transport out of surface layer into other layers, during convective and non-convective periods, than other local and non-local schemes parameterizing mixing processes in the ABL. The suggested method for calculating the in-canopy resistance for calculating the dry deposition over a vegetated surface differs remarkably from the commonly used one, particularly over forest vegetation. Discussion In this paper, we studied the performance of a non-local, turbulent, kinetic energy scheme for vertical diffusion combined with a non-local, convective mixing scheme with varying upward mixing in the atmospheric boundary layer (COM) and its impact on the concentration of pollutants calculated with chemical and air-quality models. In addition, this scheme was also compared with a commonly used, local, eddy-diffusivity scheme. Simulated concentrations of NO₂ by the COM scheme and new parameterization of the in-canopy resistance are closer to the observations when compared to those obtained from using the local eddy-diffusivity scheme. Conclusions Concentrations calculated with the COM scheme and new parameterization of in-canopy resistance, are in general higher and closer to the observations than those obtained by the local, eddy-diffusivity scheme (on the order of 15-22%). Recommendations and perspectives To examine the performance of the scheme, simulated and measured concentrations of a pollutant (NO₂) were compared for the years 1999 and 2002. The comparison was made for the entire domain used in simulations performed by the chemical European Monitoring and Evaluation Program Unified model (version UNI-ACID, rv2.0) where schemes were incorporated.
Show more [+] Less [-]Sources and emission of greenhouse gases in Danube Delta lakes Full text
2009
Pavel, Alina | Durisch-Kaiser, Edith | Balan, Sorin | Radan, Silviu | Sobek, Sebastian | Wehrli, Bernhard
Production of methane and carbon dioxide as well as methane concentrations in surface waters and emissions to the atmosphere were investigated in two flow-through lake complexes (Uzlina-Isac and Puiu-Rosu-Rosulet) in the Danube Delta during post-flood conditions in May and low water level in September 2006. Retained nutrients fuelled primary production and remineralisation of bioavailable organic matter. This led to an observable net release of methane, particularly in the lakes Uzlina, Puiu and Rosu in May. Input from the Danube River, from redbuds and benthic release contributed to CH₄ concentrations in surface waters. In addition to significant river input of CO₂, this trace gas was released via aerobic remineralisation within the water column and in top sediments. Emission patterns of CO₂ widely overlapped with those of CH₄. Generally, greenhouse gas emissions peaked in the lake complex adjacent to the Danube River in May due to strong winds and decreased with increasing hydrological distance from the Danube River. Intense remineralisation of organic matter in the Danube Delta lakes results in a net source of atmospheric greenhouse gases.
Show more [+] Less [-]Metabolism of acetaminophen (paracetamol) in plants--two independent pathways result in the formation of a glutathione and a glucose conjugate Full text
2009
Huber, Christian | Bartha, Bernadett | Harpaintner, Rudolf | Schröder, Peter
Background, aim, and scope Pharmaceuticals and their metabolites are detected in the aquatic environment and our drinking water supplies. The need for high quality drinking water is one of the most challenging problems of our times, but still only little knowledge exists on the impact of these compounds on ecosystems, animals, and man. Biological waste water treatment in constructed wetlands is an effective and low-cost alternative, especially for the treatment of non-industrial, municipal waste water. In this situation, plants get in contact with pharmaceutical compounds and have to tackle their detoxification. The mechanisms for the detoxification of xenobiotics in plants are closely related to the mammalian system. An activation reaction (phase I) is followed by a conjugation (phase II) with hydrophilic molecules like glutathione or glucose. Phase III reactions can be summarized as storage, degradation, and transport of the xenobiotic conjugate. Until now, there is no information available on the fate of pharmaceuticals in plants. In this study, we want to investigate the fate and metabolism of N-acetyl-4-aminophenol (paracetamol) in plant tissues using the cell culture of Armoracia rusticana L. as a model system. Materials and methods A hairy root culture of A. rusticana was treated with acetaminophen in a liquid culture. The formation and identification of metabolites over time were analyzed using HPLC-DAD and LC-MSn techniques. Results With LC-MS technique, we were able to detect paracetamol and identify three of its metabolites in root cells of A. rusticana. Six hours after incubation with 1 mM of acetaminophen, the distribution of acetaminophen and related metabolites in the cells resulted in 18% paracetamol, 64% paracetamol-glucoside, 17% paracetamol glutathione, and 1% of the corresponding cysteine conjugate. Discussion The formation of two independently formed metabolites in plant root cells again revealed strong similarities between plant and mammalian detoxification systems. The detoxification mechanism of glucuronization in mammals is mirrored by glucosidation of xenobiotics in plants. Furthermore, in both systems, a glutathione conjugate is formed. Due to the existence of P450 enzymes in plants, the formation of the highly reactive NAPQI intermediate is possible. Conclusions In this study, we introduce the hairy root cell culture of A. rusticana L. as a suitable model system to study the fate of acetaminophen in plant tissues. Our first results point to the direction of plants being able to take up and detoxify the model substrate paracetamol. These first findings underline the great potential of using plants for waste water treatments in constructed wetlands. Recommendations and perspectives This very first study on the detoxification of a widely used antipyretic agent in plant tissues again shows the flexibility of plant detoxification systems and their potential in waste water treatment facilities. This study covers only the very first steps of acetaminophen detoxification in plants; still, there is no data on long-term exposure as well as the possible impact of pharmaceuticals on the plant health and stress defense. Long-term experiments need to be performed to follow the fate of acetaminophen in root and leaf cells in a whole plant system, and to evaluate possible usage of plants for the remediation of acetaminophen from waste water.
Show more [+] Less [-]Part V--sorption of pharmaceuticals and personal care products Full text
2009
Pan, Bo | Ning, Ping | Xing, Baoshan
Background, aim, and scope Pharmaceuticals and personal care products (PPCPs) including antibiotics, endocrine-disrupting chemicals, and veterinary pharmaceuticals are emerging pollutants, and their environmental risk was not emphasized until a decade ago. These compounds have been reported to cause adverse impacts on wildlife and human. However, compared to the studies on hydrophobic organic contaminants (HOCs) whose sorption characteristics is reviewed in Part IV of this review series, information on PPCPs is very limited. Thus, a summary of recent research progress on PPCP sorption in soils or sediments is necessary to clarify research requirements and directions. Main features We reviewed the research progress on PPCP sorption in soils or sediments highlighting PPCP sorption different from that of HOCs. Special function of humic substances (HSs) on PPCP behavior is summarized according to several features of PPCP-soil or sediment interaction. In addition, we discussed the behavior of xenobiotic chemicals in a three-phase system (dissolved organic matter (DOM)-mineral-water). The complexity of three-phase systems was also discussed. Results Nonideal sorption of PPCPs in soils or sediments is generally reported, and PPCP sorption behavior is relatively a more complicated process compared to HOC sorption, such as the contribution of inorganic fractions, fast degradation and metabolite sorption, and species-specific sorption mechanism. Thus, mechanistic studies are urgently needed for a better understanding of their environmental risk and for pollution control. Discussion Recent research progress on nonideal sorption has not been incorporated into fate modeling of xenobiotic chemicals. A major reason is the complexity of the three-phase system. First of all, lack of knowledge in describing DOM fractionation after adsorption by mineral particles is one of the major restrictions for an accurate prediction of xenobiotic chemical behavior in the presence of DOM. Secondly, no explicit mathematical relationship between HS chemical-physical properties, and their sorption characteristics has been proposed. Last but not least, nonlinear interactions could exponentially increase the complexity and uncertainties of environmental fate models for xenobiotics. Discussion on proper simplification of fate modeling in the framework of nonlinear interactions is still unavailable. Conclusions Although the methodologies and concepts for studying HOC environmental fate could be adopted for PPCP study, their differences should be highly understood. Prediction of PPCP environmental behavior needs to combine contributions from various fractions of soils or sediments and the sorption of their metabolites and different species. Recommendations and perspectives More detailed studies on PPCP sorption in separated soil or sediment fractions are needed in order to propose a model predicting PPCP sorption in soils or sediments based on soil or sediment properties. The information on sorption of PPCP metabolites and species and the competition between them is still not enough to be incorporated into any predictive models.
Show more [+] Less [-]Endosulfan in China 2--emissions and residues Full text
2009
Jia, Hongliang | Sun, Yeqing | Li, Yi-Fan | Tian, Chongguo | Wang, Degao | Yang, Meng | Ding, Yongshen | Ma, Jianmin
Background, aim, and scope Endosulfan is one of the organochlorine pesticides (OCPs) and also a candidate to be included in a group of new persistent organic pollutants (UNEP 2007). The first national endosulfan usage inventories in China with 1/4° longitude by 1/6° latitude resolution has been reported in an accompanying paper. In the second part of the paper, we compiled the gridded historical emissions and soil residues of endosulfan in China from the usage inventories. Based on the residue/emission data, gridded concentrations of endosulfan in Chinese soil and air have been calculated. These inventories will provide valuable data for the further study of endosulfan. Methods Emission and residue of endosulfan were calculated from endosulfan usage by using a simplified gridded pesticide emission and residue model--SGPERM, which is an integrated modeling system combining mathematical model, database management system, and geographic information system. By using the emission and residue inventories, annual air and soil concentrations of endosulfan in each cell were determined. Results and discussion Historical gridded emission and residue inventories of α- and β-endosulfan in agricultural soil in China with 1/4° longitude by 1/6° latitude resolution have been created. Total emissions were around 10,800 t, with α-endosulfan at 7,400 t and β-endosulfan at 3,400 t from 1994 to 2004. The highest residues were 140 t for α-endosulfan and 390 t for β-endosulfan, and the lowest residues were 0.7 t for α-endosulfan and 170 t for β-endosulfan in 2004 in Chinese agricultural soil where endosulfan was applied. Based on the emission and residue inventories, concentrations of α- and β-endosulfan in Chinese air and agricultural surface soil were also calculated for each grid cell. We have estimated annual averaged air concentrations and the annual minimum and maximum soil concentrations across China. The real concentrations will be different from season to season. Although our model does not consider the transport of the insecticide in the atmosphere, which could be very important in some areas during some special time, the estimated concentrations of endosulfan in Chinese air and soil derived from the endosulfan emission and residue inventories are in general consistent with the published monitoring data. Conclusions To our knowledge, this work is the first inventory of this kind for endosulfan published on a national scale. Concentrations of the chemical in Chinese air and agricultural surface soil were calculated for each grid cell. Results show that the estimated concentrations of endosulfan in Chinese air and soil agree reasonably well with the monitoring data in general. Recommendations and perspectives The gridded endosulfan emission/residue inventories and also the air and soil concentration inventories created in this study will be updated upon availability of new information, including usage and monitoring data. The establishment of these inventories for the OCP is important for both scientific communities and policy makers.
Show more [+] Less [-]Endocrine disruptors in bottled mineral water: total estrogenic burden and migration from plastic bottles Full text
2009
Wagner, Martin | Oehlmann, Jörg
Background, aim, and scope Food consumption is an important route of human exposure to endocrine-disrupting chemicals. So far, this has been demonstrated by exposure modeling or analytical identification of single substances in foodstuff (e.g., phthalates) and human body fluids (e.g., urine and blood). Since the research in this field is focused on few chemicals (and thus missing mixture effects), the overall contamination of edibles with xenohormones is largely unknown. The aim of this study was to assess the integrated estrogenic burden of bottled mineral water as model foodstuff and to characterize the potential sources of the estrogenic contamination. Materials, methods, and results In the present study, we analyzed commercially available mineral water in an in vitro system with the human estrogen receptor alpha and detected estrogenic contamination in 60% of all samples with a maximum activity equivalent to 75.2 ng/l of the natural sex hormone 17β-estradiol. Furthermore, breeding of the molluskan model Potamopyrgus antipodarum in water bottles made of glass and plastic [polyethylene terephthalate (PET)] resulted in an increased reproductive output of snails cultured in PET bottles. This provides first evidence that substances leaching from plastic food packaging materials act as functional estrogens in vivo. Discussion and conclusions Our results demonstrate a widespread contamination of mineral water with xenoestrogens that partly originates from compounds leaching from the plastic packaging material. These substances possess potent estrogenic activity in vivo in a molluskan sentinel. Overall, the results indicate that a broader range of foodstuff may be contaminated with endocrine disruptors when packed in plastics.
Show more [+] Less [-]Adapting a geographical information system-based water resource management to the needs of the Romanian water authorities Full text
2009
Soutter, Marc | Alexandrescu, Maria | Schenk, Colin | Drobot, Radu
Background, aim, and scope The need for global and integrated approaches to water resources management, both from the quantitative and the qualitative point of view, has long been recognized. Water quality management is a major issue for sustainable development and a mandatory task with respect to the implementation of the European Water Framework Directive as well as the Swiss legislation. However, data modelling to develop relational databases and subsequent geographic information system (GIS)-based water management instruments are a rather recent and not that widespread trend. The publication of overall guidelines for data modelling along with the EU Water Framework Directive is an important milestone in this area. Improving overall water quality requires better and more easily accessible data, but also the possibility to link data to simulation models. Models are to be used to derive indicators that will in turn support decision-making processes. For this whole chain to become effective at a river basin scale, all its components have to become part of the current daily practice of the local water administration. Any system, tool, or instrument that is not designed to meet, first of all, the fundamental needs of its primary end-users has almost no chance to be successful in the longer term. Materials and methods Although based on a pre-existing water resources management system developed in Switzerland, the methodological approach applied to develop a GIS-based water quality management system adapted to the Romanian context followed a set of well-defined steps: the first and very important step is the assessment of needs (on the basis of a careful analysis of the various activities and missions of the water administration and other relevant stakeholders in water management related issues). On that basis, a conceptual data model (CDM) can be developed, to be later on turned into a physical database. Finally, the specifically requested additional functionalities (i.e. functionalities not provided by classical commercial GIS software), also identified during the assessment of needs, are developed. This methodology was applied, on an experimental basin, in the Ialomita River basin. Results The results obtained from this action-research project consist of a set of tangible elements, among which (1) a conceptual data model adapted to the Romanian specificities regarding water resources management (needs, data availability, etc.), (2) a related spatial relational database (objects and attributes in tables, links, etc.), that can be used to store the data collected, among others, by the water administration, and later on exploited with geographical information systems, (3) a toolbar (in the ESRI environment) offering the requested data processing and visualizing functionalities. Lessons learned from this whole process can be considered as additional, although less tangible, results. Discussion The applied methodology is fairly classical and did not come up with revolutionary results. Actually, the interesting aspects of this work are, on the one hand, and obviously, the fact that it produced tools matching the needs of the local (if not national) water administration (i.e. with a good chance of being effectively used in the day-to-day practice), and, on the other hand, the adaptations and adjustments that were needed both at the staff level and in technical terms. Conclusions This research showed that a GIS-based water management system needs to be backed by some basic data management tools that form the necessary support upon which a GIS can be deployed. The main lesson gained is that technology transfer has to pay much attention to the differences in existing situations and backgrounds in general, and therefore must be able to show much flexibility. The fact that the original objectives could be adapted to meet the real needs of the local end-users is considered as a major aspect in achieving a successful adaptation and development of water resources management tools. Time needed to setup things in real life was probably the most underestimated aspect in this technology transfer process. Recommendations and perspectives The whole material produced (conceptual data model, database and GIS tools) was disseminated among all river basin authorities in Romania on the behalf of the national water administration (ANAR). The fact that further developments, for example, to address water quantity issues more precisely, as envisaged by ANAR, can be seen as an indication that this project succeeded in providing an appropriate input to improve water quality in Romania on the long term.
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