Sample records for ecotoxicological effects extrapolation
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Developing integral projection models for aquatic ecotoxicology
Extrapolating laboratory measured effects of chemicals to ecologically relevant scales is a fundamental challenge in ecotoxicology. In addition to influencing survival in the wild (e.g., over-winter survival) size has been shown to control onset of reproduction for the toxicologi...
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Adverse Outcome Pathways and Extrapolation Tools to Advance the Three Rs in Ecotoxicology
Adverse outcome pathways (AOPs) are conceptual frameworks for identifying and organizing predictive and causal linkages between cellular-level responses and endpoints conventionally considered in ecological risk assessment (e.g., effects on survival, growth/development, and repro...
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Procedural Guidelines for Ecological Risk Assessments at U.S. Army Sites. Volume 1.
1994-12-01
altered chemically or physically. Stressors may also result from management practices such as harvesting of fishery or forest resources, or cultivation ...Inferring population-level significance from individual- level effects: An extrapolation from fisheries science to ecotoxicology . p. 289-300. In G.W
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A significant challenge in ecotoxicology has been determining chemical hazards to species with limited or no toxicity data. Currently, extrapolation tools like U.S. EPA’s Web-based Interspecies Correlation Estimation (Web-ICE; www3.epa.gov/webice) models categorize toxicity...
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Ecotoxicology for risk assessment in arid zones: some key issues.
Everts, J W
1997-01-01
In the hot arid zones of the world, ecotoxicological research is in statu nascendi. In these zones, the major sources of contamination by toxicants are: (1) plant protection and vector control in wet zones; (2) large-scale crop protection campaigns in dry and ephemeral wet zones; (3) refuse and obsolete pesticides in dry zones; and (4) mining. Economic development in many of these zones requires an adequate knowledge of certain basic principles, i.e., where extrapolating existing knowledge does not apply. The vulnerability of ecosystems to contaminants is closely related to water flow. In dry areas, species are susceptible to factors that interfere with the ecophysiological properties regulating water loss. Most hot arid areas are found at low latitudes where temperatures show striking extremes both in time and space. Living organisms are physiologically resistant and/or show adaptive behavior to these temperature extremes. Very little is known about the effects of toxicants on these key resistant and adaptive functions, although by extrapolation a few assumptions can be made. The effects of hyperthermia, for instance, can be aggravated by GSH depleting substances, and the temporary disabling effects characteristic of many pesticides may prove fatal under these circumstances. Most wet areas show a spatial concentration of both human activity and wildlife. In mesic zones, the contamination of water represents a health risk to both humans and other living organisms. The vast majority of aquatic communities are those inhabiting temporary pools and streams. Their populations are characterized by short reproductive cycles and/or long dormant stages. Toxicants affecting growth in these areas have been shown to have a deleterious effect. In a synthesis of existing knowledge the most prominent gaps are identified and priorities for further research are made.
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Wildlife toxicity extrapolations: NOAEL versus LOAEL
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fairbrother, A.; Berg, M. van den
1995-12-31
Ecotoxicological assessments must rely on the extrapolation of toxicity data from a few indicator species to many species of concern. Data are available from laboratory studies (e.g., quail, mallards, rainbow trout, fathead minnow) and some planned or serendipitous field studies of a broader, but by no means comprehensive, suite of species. Yet all ecological risk assessments begin with an estimate of risk based on information gleaned from the literature. One is then confronted with the necessity of extrapolating toxicity information from a limited number of indicator species to all organisms of interest. This is a particularly acute problem when tryingmore » to estimate hazards to wildlife in terrestrial systems as there is an extreme paucity of data for most chemicals in all but a handful of species. This section continues the debate by six panelists of the ``correct`` approach for determining wildlife toxicity thresholds by debating which toxicity value should be used for setting threshold criteria. Should the lowest observable effect level (LOAEL) be used or is it more appropriate to use the no observable effect level (NOAEL)? What are the short-comings of using either of these point estimates? Should a ``benchmark`` approach, similar to that proposed for human health risk assessments, be used instead, where an EC{sub 5} or EC{sub 10} and associated confidence limits are determined and then divided by a safety factor? How should knowledge of the slope of the dose-response curve be incorporated into determination of toxicity threshold values?« less
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Contaminant effect endpoints in terrestrial vertebrates at and above the individual level
Rattner, B.A.; Cohen, J.B.; Golden, N.H.; Albers, P.H.; Heinz, G.H.; Ohlendorf, H.M.
2000-01-01
Use of biochemical, physiological, anatomical, reproductive and behavioral characteristics of wild terrestrial vertebrates to assess contaminant exposure and effects has become commonplace over the past 3 decades. At the level of the individual organism, response patterns have been associated with and sometimes causally linked to contaminant exposure. However, such responses at the organismal level are rarely associated with or causally linked to effects at the population level. Although the ultimate goal of ecotoxicology is the protection of populations, communities, and ecosystems, most of the existing science and regulatory legislation focus on the level of the individual. Consequently, much of this overview concentrates on contaminant effects at the organismal level, with some extrapolation to higher-level effects. In this chapter, we review the state of the science for the evaluation of biotic end-points used to assess contaminant exposure and effects at or above the level of the individual. In addition, we describe extant contaminant concentration thresholds, guidelines, or standards (toxicant criteria) in environmental matrices (e.g., water, soil, sediment, foods) that have been developed to protect wild terrestrial vertebrates. Suggestions are provided to develop and embellish the use and value of such endpoints and criteria for extrapolation of effects to higher levels of biological organization. Increasing focus on populations, communities, and ecosystems is needed to develop biologically meaningful regulatory guidelines that will protect natural resources.
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Slaughter, Andrew R; Palmer, Carolyn G; Muller, Wilhelmine J
2007-04-01
In aquatic ecotoxicology, acute to chronic ratios (ACRs) are often used to predict chronic responses from available acute data to derive water quality guidelines, despite many problems associated with this method. This paper explores the comparative protectiveness and accuracy of predicted guideline values derived from the ACR, linear regression analysis (LRA), and multifactor probit analysis (MPA) extrapolation methods applied to acute toxicity data for aquatic macroinvertebrates. Although the authors of the LRA and MPA methods advocate the use of extrapolated lethal effects in the 0.01% to 10% lethal concentration (LC0.01-LC10) range to predict safe chronic exposure levels to toxicants, the use of an extrapolated LC50 value divided by a safety factor of 5 was in addition explored here because of higher statistical confidence surrounding the LC50 value. The LRA LC50/5 method was found to compare most favorably with available experimental chronic toxicity data and was therefore most likely to be sufficiently protective, although further validation with the use of additional species is needed. Values derived by the ACR method were the least protective. It is suggested that there is an argument for the replacement of ACRs in developing water quality guidelines by the LRA LC50/5 method.
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[Research advances in eco-toxicological diagnosis of soil pollution].
Liu, Feng; Teng, Hong-Hui; Ren, Bai-Xiang; Shi, Shu-Yun
2014-09-01
Soil eco-toxicology provides a theoretical basis for ecological risk assessment of contaminated soils and soil pollution control. Research on eco-toxicological effects and molecular mechanisms of toxic substances in soil environment is the central content of the soil eco-toxicology. Eco-toxicological diagnosis not only gathers all the information of soil pollution, but also provides the overall toxic effects of soil. Therefore, research on the eco-toxicological diagnosis of soil pollution has important theoretical and practical significance. Based on the research of eco-toxicological diagnosis of soil pollution, this paper introduced some common toxicological methods and indicators, with the advantages and disadvantages of various methods discussed. However, conventional biomarkers can only indicate the class of stress, but fail to explain the molecular mechanism of damage or response happened. Biomarkers and molecular diagnostic techniques, which are used to evaluate toxicity of contaminated soil, can explore deeply detoxification mechanisms of organisms under exogenous stress. In this paper, these biomarkers and techniques were introduced systematically, and the future research trends were prospected.
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Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John
1995-01-01
The Handbook of Ecotoxicology offers 34 chapters with contributions from over 50 selected international experts. The book is divided into four major sections: I. Quantifying and Measuring Ecotoxicological Effects, II. Contaminant Sources and Effects, III. Case Histories and Ecosystem Surveys, and IV. Methods for Making Estimates and Predictability in Ecotoxicology. Concepts and methodology are presented for many types of aquatic and terrestrial ecotoxicity test protocols for both controlled and field assessments. Chapters are offered on such diverse topics as sediment and soil ecotoxicity, landscape indicators, biomonitoring, and use of current bioindicators. The roles of deforestation and global warming, pathogens and disease in ecotoxicology, abiotic factors, urban runoff, predictive ecotoxicology, population modeling, and restoration ecology are discussed. This book was designed to serve as a reference book for students entering the fields of ecotoxicology, aquatic toxicology, terrestrial wildlife toxicology, and other environmental sciences. Many portions of this handbook will serve as a convenient reference text for established investigators, resource managers, and those involved in risk assessment and risk management within regulatory agencies and the private sector.
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Hommen, Udo; Baveco, J M Hans; Galic, Nika; van den Brink, Paul J
2010-07-01
Several European directives and regulations address the environmental risk assessment of chemicals. We used the protection of freshwater ecosystems against plant protection products, biocidal products, human and veterinary pharmaceuticals, and other chemicals and priority substances under the Water Framework Directive as examples to explore the potential of ecological effect models for a refined risk assessment. Our analysis of the directives, regulations, and related guidance documents lead us to distinguish the following 5 areas for the application of ecological models in chemical risk assessment: 1) Extrapolation of organism-level effects to the population level: The protection goals are formulated in general terms, e.g., avoiding "unacceptable effects" or "adverse impact" on the environment or the "viability of exposed species." In contrast, most of the standard ecotoxicological tests provide data only on organism-level endpoints and are thus not directly linked to the protection goals which focus on populations and communities. 2) Extrapolation of effects between different exposure profiles: Especially for plant protection products, exposure profiles can be very variable and impossible to cover in toxicological tests. 3) Extrapolation of recovery processes: As a consequence of the often short-term exposures to plant protection products, the risk assessment is based on the community recovery principle. On the other hand, assessments under the other directives assume a more or less constant exposure and are based on the ecosystem threshold principle. 4) Analysis and prediction of indirect effects: Because effects on 1 or a few taxa might have consequences on other taxa that are not directly affected by the chemical, such indirect effects on communities have to be considered. 5) Prediction of bioaccumulation within food chains: All directives take the possibility of bioaccumulation, and thus secondary poisoning within the food chain, into account. (c) 2010 SETAC.
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Tromson, Clara; Bulle, Cécile; Deschênes, Louise
2017-03-01
In life cycle assessment (LCA), the potential terrestrial ecotoxicity effect of metals, calculated as the effect factor (EF), is usually extrapolated from aquatic ecotoxicological data using the equilibrium partitioning method (EqP) as it is more readily available than terrestrial data. However, when following the AMI recommendations (i.e. with at least enough species that represents three different phyla), there are not enough terrestrial data for which soil properties or metal speciation during ecotoxicological testing are specified to account for the influence of soil property variations on metal speciation when using this approach. Alternatively, the TBLM (Terrestrial Biotic Ligand Model) has been used to determine an EF that accounts for speciation, but is not available for metals; hence it cannot be consistently applied to metals in an LCA context. This paper proposes an approach to include metal speciation by regionalizing the EqP method for Cu, Ni and Zn with a geochemical speciation model (the Windermere Humic Aqueous Model 7.0), for 5213 soils selected from the Harmonized World Soil Database. Results obtained by this approach (EF EqP regionalized ) are compared to the EFs calculated with the conventional EqP method, to the EFs based on available terrestrial data and to the EFs calculated with the TBLM (EF TBLM regionalized ) when available. The spatial variability contribution of the EF to the overall spatial variability of the characterization factor (CF) has been analyzed. It was found that the EFs EqP regionalized show a significant spatial variability. The EFs calculated with the two non-regionalized methods (EqP and terrestrial data) fall within the range of the EFs EqP regionalized . The EFs TBLM regionalized cover a larger range of values than the EFs EqP regionalized but the two methods are not correlated. This paper highlights the importance of including speciation into the terrestrial EF and shows that using the regionalized EqP approach is not an acceptable proxy for terrestrial ecotoxicological data even if it can be applied to all metals. Copyright © 2016. Published by Elsevier B.V.
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Handbook of ecotoxicology, second edition
Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John
2003-01-01
Handbook of Ecotoxicology, Second Edition focuses on toxic substances and how they affect ecosystems worldwide. It presents methods for quantifying and measuring ecotoxicological effects in the field and in the lab, as well as methods for estimating, predicting, and modeling in ecotoxicology studies. Completely revised and updated with 18 new chapters, this second edition includes contributions from over 75 international experts. Also, a Technical Review Board reviewed all manuscripts for accuracy and currency. This authoritative work is the definitive reference for students, researchers, consultants, and other professionals in the environmental sciences, toxicology, chemistry, biology, and ecology - in academia, industry, and government.
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Ecotoxicological evaluation of areas polluted by mining activities
NASA Astrophysics Data System (ADS)
García-Lorenzo, M. L.; Martínez-Sánchez, M. J.; Pérez-Sirvent, C.; Molina, J.
2009-04-01
Determination of the contaminant content is not enough to evaluate the toxic effects or to characterise contaminated sites, because such a measure does not reflect the ecotoxicological danger in the environment and does not provide information on the effects of the chemical compounds. To estimate the risk of contaminants, chemical methods need to be complemented with biological methods. Therefore, ecotoxicological testing may be a useful approach for assessing the toxicity as a complement to chemical analysis. The aim of this study was to develop a battery of bioassays for the ecotoxicological screening of areas polluted by mining activities. Particularly, the toxicity of water samples, sediments and their pore-water extracts was evaluated by using three assays: bacteria, plants and ostracods. Moreover, the possible relationship between observed toxicity and results of chemical analysis was studied. The studied area, Sierra Minera, is close to the mining region of La Uni
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Sheffield, S.R.; Sawicka-Kapusta, K.; Cohen, J.B.; Rattner, B.A.; Shore, Richard F.; Rattner, Barnett A.
2001-01-01
This comprehensive review examines the extensive literature on wild rodents and lagomorphs as biomonitors of environmental contamination. This chapter covers studies dealing with exposure and effects of environmental contaminants on rodent and lagomorph species, including pesticides (organochlorines, organophosphorus and carbamate compounds, herbicides, plant growth regulators, fungicides, and rodenticides), other organic chemicals, metals, radionuclides, and other miscellaneous contaminants. Many research needs become evident when reviewing ecotoxicological data for rodents and lagomorphs, the most striking being the paucity of information on rodent families other than Muridae (mice and rats). While our ability to qualitatively extrapolate effects observed in laboratory studies to field situations is good for a variety of contaminants, quantitative predictions of dose-response relationships are poor because inter-specific variation and differences in exposure patterns between laboratory and wild species to toxicants are for the most part unknown. More sophisticated comparative toxicity studies need to be undertaken that build on previous work in order to develop a database of information, to account for and model differences in exposure pathways, to document interactions among multiple stressors, to generate data establishing thresholds, critical concentrations, and diagnostic guidelines, and even to develop physiologically-based toxicokinetic models. Such efforts may enhance our ability to predict effects on wild populations, including threatened and endangered species.
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This is an editorial in ET&C describing the newer pathway-specific test methods for EDCs and their effect on ecotoxicology. Work conducted to support the development and application of these types of assays promises to be an important catalyst to advance the field of ecotoxicolo...
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2001-01-01
An international group of 32 scientists has critically reviewed the scientific literature on exposure and effects of environmental contaminants in wild mammals. The underlying theme of this text is encompassed by the following four questions: What exactly do we know about environmental contaminants in mammals? What are the commonalities and differences between mammal orders/species in the effects that contaminants have? How and to what degree of accuracy can we predict the adverse effects of environmental contaminants on mammalian wildlife? How significant are contaminant insults compared with other density-independent and -dependent factors such as habitat loss, climatic factors and disease? The book is organized three topical sections including introductory chapters that provide a background on environmental contaminants and the mammalian orders, eight taxonomic chapters discussing all aspects of the exposure to and effects of contaminants in mammalian orders, and four thematic chapters that review and discuss generic issues including biomarkers, prediction and extrapolation of exposure and effects, hazard and risk assessment, and the relative significance of contaminants on mammals compared with other commonly encountered stressors. A final a summary chapter identifies phylogenetic trends, critical data gaps, and overarching research needs. Although the absolute number of toxicological studies in domesticated and wild mammals eclipses that wildlife species, a detailed examination of our knowledge base reveals that information for 'wild' birds is actually greater than that for 'wild' mammals. Of the various mammalian taxa, ecotoxicological data is most noticeably lacking for marsupials and monotremes. In contrast, rodents (comprising 43% of all mammal species) have been studied extensively, despite evidence of their tolerance to some organochlorine compounds, rodenticides, and even radionuclides. Mammalian species at greatest risk of exposure include those that consume a high percentage of their body weight on a daily basis. Aquatic mammals tend to bioaccumulate tremendous burdens of lipophilic contaminants, although storage in their fat depots may actually limit toxicity. Carnivores appear to be more sensitive to adverse effects of environmental contaminants than herbivores. Remarkably few of the thousands of compounds manufactured worldwide have been toxicologically evaluated in wild mammals, and concentrations of even fewer have been monitored in tissues.
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Microarray, proteomic, and metabonomic technologies are becoming increasingly accessible as tools for ecotoxicology research. Effective use of these technologies will depend, at least in part, on the ability to apply these techniques within a paradigm of hypothesis driven researc...
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Potential ecotoxicological effects of elevated bicarbonate ion concentrations on marine organisms.
Gim, Byeong-Mo; Hong, Seongjin; Lee, Jung-Suk; Kim, Nam-Hyun; Kwon, Eun-Mi; Gil, Joon-Woo; Lim, Hyun-Hwa; Jeon, Eui-Chan; Khim, Jong Seong
2018-05-25
Recently, a novel method for carbon capture and storage has been proposed, which converts gaseous CO 2 into aqueous bicarbonate ions (HCO 3 - ), allowing it to be deposited into the ocean. This alkalinization method could be used to dispose large amounts of CO 2 without acidifying seawater pH, but there is no information on the potential adverse effects of consequently elevated HCO 3 - concentrations on marine organisms. In this study, we evaluated the ecotoxicological effects of elevated concentrations of dissolved inorganic carbon (DIC) (max 193 mM) on 10 marine organisms. We found species-specific ecotoxicological effects of elevated DIC on marine organisms, with EC50-DIC (causing 50% inhibition) of 11-85 mM. The tentative criteria for protecting 80% of individuals of marine organisms are suggested to be pH 7.8 and 11 mM DIC, based on acidification data previously documented and alkalinization data newly obtained from this study. Overall, the results of this study are useful for providing baseline information on ecotoxicological effects of elevated DIC on marine organisms. More complementary studies are needed on the alkalinization method to determine DIC effects on seawater chemistry and marine organisms. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Genomics in Regulatory Ecotoxicology: Applications and Challenges: Publication Announcement
In September, 2005, a workshop was held at the original home of the SETAC Pellston series, in Pellston, MI. The goal of this workshop was to explore whether and how genomics could be effectively applied to challenges in regulatory ecotoxicology. The book emanating from the worksh...
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2001-07-06
Chemistry Agnes Renoux, Ph.D. Ecotoxicology Bernard Lachance, Ph. D. Ecotoxicology Ping Gong, Ph. D. Ecotoxicology Pierre-Yves Robidoux, Ph.D... Ecotoxicology Tamara Sheremata, Ph. D. Env. Engineering Diane Fournier, Ph.D. Microbiology Annamaria Halasz, M.Sc. Chemistry Louise Paquet, B.Sc...12 Chapter 4: Applied Ecotoxicology
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There are multiple sources of biological and technical variation in a typical ecotoxicology study that may not be revealed by traditional endpoints but that become apparent in an omics dataset. As researchers increasingly apply omics technologies to environmental studies, it will...
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Efroymson, Rebecca Ann; Giffen, Neil R; Morrill, Valerie
Managing sites contaminated with munitions constituents is an international challenge. Although the choice of approach and the use of Ecological Risk Assessment (ERA) tools may vary from country to country, the assurance of quality and the direction of ecotoxicological research are universally recognized as shared concerns. Drawing on a multidisciplinary team of contributors, 'Ecotoxicology of Explosives' provides comprehensive and critical reviews available to date on fate, transport, and effects of explosives. The book delineates the state of the science of the ecotoxicology of explosives, past, present, and recently developed. It reviews the accessible fate and ecotoxicological data for energetic materialsmore » (EMs) and the methods for their development. The chapters characterize the fate of explosives in the environment, then provide information on their ecological effects in key environmental media, including aquatic, sedimentary, and terrestrial habitats. The book also discusses approaches for assembling these lines of evidence for risk assessment purposes. The chapter authors have critically examined the peer-reviewed literature to identify and prioritize the knowledge gaps and to recommend future areas of research. The editors include a review of the genotoxic effects of the EMs and the cellular and molecular mechanisms underlying the toxicity of these chemicals. They also discuss the transport, transformation, and degradation pathways of these chemicals in the environment that underlie the potential hazardous impact and bioaccumulation of EMs in different terrestrial and aquatic ecological receptors. This information translates into practical applications for the environmental risk assessment of EM-contaminated sites and into recommendations for the sustainable use of defense installations.« less
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Groh, Ksenia J; Carvalho, Raquel N; Chipman, James K; Denslow, Nancy D; Halder, Marlies; Murphy, Cheryl A; Roelofs, Dick; Rolaki, Alexandra; Schirmer, Kristin; Watanabe, Karen H
2015-02-01
To elucidate the effects of chemicals on populations of different species in the environment, efficient testing and modeling approaches are needed that consider multiple stressors and allow reliable extrapolation of responses across species. An adverse outcome pathway (AOP) is a concept that provides a framework for organizing knowledge about the progression of toxicity events across scales of biological organization that lead to adverse outcomes relevant for risk assessment. In this paper, we focus on exploring how the AOP concept can be used to guide research aimed at improving both our understanding of chronic toxicity, including delayed toxicity as well as epigenetic and transgenerational effects of chemicals, and our ability to predict adverse outcomes. A better understanding of the influence of subtle toxicity on individual and population fitness would support a broader integration of sublethal endpoints into risk assessment frameworks. Detailed mechanistic knowledge would facilitate the development of alternative testing methods as well as help prioritize higher tier toxicity testing. We argue that targeted development of AOPs supports both of these aspects by promoting the elucidation of molecular mechanisms and their contribution to relevant toxicity outcomes across biological scales. We further discuss information requirements and challenges in application of AOPs for chemical- and site-specific risk assessment and for extrapolation across species. We provide recommendations for potential extension of the AOP framework to incorporate information on exposure, toxicokinetics and situation-specific ecological contexts, and discuss common interfaces that can be employed to couple AOPs with computational modeling approaches and with evolutionary life history theory. The extended AOP framework can serve as a venue for integration of knowledge derived from various sources, including empirical data as well as molecular, quantitative and evolutionary-based models describing species responses to toxicants. This will allow a more efficient application of AOP knowledge for quantitative chemical- and site-specific risk assessment as well as for extrapolation across species in the future. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Libralato, Giovanni; Losso, Chiara; Arizzi Novelli, Alessandra; Citron, Marta; Della Sala, Stefano; Zanotto, Emanuele; Cepak, Franka; Volpi Ghirardini, Annamaria
2008-12-01
This work assesses the ecotoxicological effects of polluted sediment after a decontamination treatment process using a new sediment washing technique. Sediment samples were collected from four sites in Marghera Port industrial channels (Venice, Italy). Ecotoxicological evaluations were performed with Vibrio fischeri and Crassostrea gigas bioassays. Whole sediment and elutriate were deemed as the most suitable environmental matrices for this study. Toxicity scores developed in the Lagoon of Venice for V. fischeri on whole sediment and for C. gigas on elutriate were considered for the final ranking of samples. Ecotoxicological results showed that the treated sediment samples presented both acute and sub-chronic toxicities, which were mainly attributed to the presence of some remaining chemicals such as metals and polyaromatic hydrocarbons. The acute toxicity ranged from low to medium, while the sub-chronic one from absent to very high, suggesting that treated sediments could not be reused in direct contact with seawater.
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Philippe, Charlotte; Grégoir, Arnout F; Janssens, Lizanne; Pinceel, Tom; De Boeck, Gudrun; Brendonck, Luc
2017-10-01
Nothobranchius furzeri is a promising model for ecotoxicological research due to the species' short life cycle and the production of drought-resistant eggs. Although the species is an emerging vertebrate fish model for several fundamental as well as applied research domains, its potential for ecotoxicological research has not yet been tested. The aim of this study was to characterise the acute and chronic sensitivity of this species to copper as compared to other model organisms. Effects of both acute and chronic copper exposure were tested on survival, life history and physiological traits. We report a 24h-LC 50 of 53.93µg Cu/L, which is situated within the sensitivity range of other model species such as Brook Trout, Fathead Minnow and Rainbow Trout. Moreover, in the full life cycle exposure, we show that an exposure concentration of 10.27µg/L did not cause acute adverse effects (96h), but did cause mortality after prolonged exposure (3-4 weeks). Also chronic, sublethal effects were observed, such as a reduction in growth rate, delayed maturation and postponed reproduction. Based on our results, we define the NOEC at 6.68µg Cu/L, making N. furzeri more sensitive to copper as compared to Brook Trout and Fathead Minnow. We found stimulatory effects on peak fecundity at subinhibitory levels of copper concentrations (hormesis). Finally, we found indications for detoxifying and copper-excreting mechanisms, demonstrating the ability of the fish to cope with this essential metal, even when exposed to stressful amounts. The successful application of current ecotoxicological protocols on N. furzeri and its sensitivity range comparable to that of other model organisms forms the basis to exploit this species in further ecotoxicological practices. Copyright © 2017 Elsevier Inc. All rights reserved.
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Emerging Concern from Short-Term Textile Leaching: A Preliminary Ecotoxicological Survey.
Lofrano, G; Libralato, G; Carotenuto, M; Guida, M; Inglese, M; Siciliano, A; Meriç, S
2016-11-01
Textile dyes and their residues gained growing attention worldwide. Textile industry is a strong water consumer potentially releasing xenobiotics from washing and rinsing procedures during finishing processes. On a decentralised basis, also final consumers generate textile waste streams. Thus, a procedure simulating home washing with tap water screened cotton textiles leachates (n = 28) considering physico-chemical (COD, BOD 5 , and UV absorbance) and ecotoxicological data (Daphnia magna, Pseudokirchneriella subcapitata and Lepidium sativum). Results evidenced that: (i) leachates presented low biodegradability levels; (ii) toxicity in more than half leachates presented slight acute or acute effects; (iii) the remaining leachates presented "no effect" suggesting the use of green dyes/additives, and/or well established finishing processes; (iv) no specific correlations were found between traditional physico-chemical and ecotoxicological data. Further investigations will be necessary to identify textile residues, and their potential interactions with simulated human sweat in order to evidence potential adverse effects on human health.
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Beyer, W. Nelson; Meador, James P.; Meador, James P.
2011-01-01
Ecotoxicology is the study of the movement of environmental contaminants through ecosystems and their effects on plants and animals. Examining tissue residues of these contaminants in biota is basic to ecotoxicology, both for understanding the movement of contaminants within organisms and through food chains, and for understanding and quantifying injuries to organisms and their communities. This book provides guidance on interpreting tissue concentrations of environmental contaminants.
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Ecotoxicological assessment of antibiotics: A call for improved consideration of microorganisms.
Brandt, Kristian K; Amézquita, Alejandro; Backhaus, Thomas; Boxall, Alistair; Coors, Anja; Heberer, Thomas; Lawrence, John R; Lazorchak, James; Schönfeld, Jens; Snape, Jason R; Zhu, Yong-Guan; Topp, Edward
2015-12-01
Antibiotics play a pivotal role in the management of infectious disease in humans, companion animals, livestock, and aquaculture operations at a global scale. Antibiotics are produced, consumed, and released into the environment at an unprecedented scale causing concern that the presence of antibiotic residues may adversely impact aquatic and terrestrial ecosystems. Here we critically review the ecotoxicological assessment of antibiotics as related to environmental risk assessment (ERA). We initially discuss the need for more specific protection goals based on the ecosystem service concept, and suggest that the ERA of antibiotics, through the application of a mode of toxic action approach, should make more use of ecotoxicological endpoints targeting microorganisms (especially bacteria) and microbial communities. Key ecosystem services provided by microorganisms and associated ecosystem service-providing units (e.g. taxa or functional groups) are identified. Approaches currently available for elucidating ecotoxicological effects on microorganisms are reviewed in detail and we conclude that microbial community-based tests should be used to complement single-species tests to offer more targeted protection of key ecosystem services. Specifically, we propose that ecotoxicological tests should not only assess microbial community function, but also microbial diversity (‘species’ richness) and antibiotic susceptibility. Promising areas for future basic and applied research of relevance to ERA are highlighted throughout the text. In this regard, the most fundamental knowledge gaps probably relate to our rudimentary understanding of the ecological roles of antibiotics in nature and possible adverse effects of environmental pollution with subinhibitory levels of antibiotics.
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Medicines, shaken and stirred: a critical review on the ecotoxicology of pharmaceutical mixtures
Backhaus, Thomas
2014-01-01
Analytical monitoring surveys routinely confirm that organisms in the environment are exposed to complex multi-component pharmaceutical mixtures. We are hence tasked with the challenge to take this into consideration when investigating the ecotoxicology of pharmaceuticals. This review first provides a brief overview of the fundamental approaches for mixture toxicity assessment, which is then followed by a critical review on the empirical evidence that is currently at hand on the ecotoxicology of pharmaceutical mixtures. It is concluded that, while the classical concepts of concentration addition and independent action (response addition) provide a robust scientific footing, several knowledge gaps remain. This includes, in particular, the need for more and better empirical data on the effects of pharmaceutical mixtures on soil organisms as well as marine flora and fauna, and exploring the quantitative consequences of toxicokinetic, toxicodynamic and ecological interactions. Increased focus should be put on investigating the ecotoxicology of pharmaceutical mixtures in environmentally realistic settings. PMID:25405972
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Brown, Alastair; Wright, Roseanna; Mevenkamp, Lisa; Hauton, Chris
2017-10-01
Exploration of deep-sea mineral resources is burgeoning, raising concerns regarding ecotoxicological impacts on deep-sea fauna. Assessing toxicity in deep-sea species is technologically challenging, which promotes interest in establishing shallow-water ecotoxicological proxy species. However, the effects of temperature and hydrostatic pressure on toxicity, and how adaptation to deep-sea environmental conditions might moderate these effects, are unknown. To address these uncertainties we assessed behavioural and physiological (antioxidant enzyme activity) responses to exposure to copper-spiked artificial sediments in a laboratory experiment using a shallow-water holothurian (Holothuria forskali), and in an in situ experiment using a deep-sea holothurian (Amperima sp.). Both species demonstrated sustained avoidance behaviour, evading contact with contaminated artificial sediment. However, A. sp. demonstrated sustained avoidance of 5mgl -1 copper-contaminated artificial sediment whereas H. forskali demonstrated only temporary avoidance of 5mgl -1 copper-contaminated artificial sediment, suggesting that H. forskali may be more tolerant of metal exposure over 96h. Nonetheless, the acute behavioural response appears consistent between the shallow-water species and the deep-sea species, suggesting that H. forskali may be a suitable ecotoxicological proxy for A. sp. in acute (≤24h) exposures, which may be representative of deep-sea mining impacts. No antioxidant response was observed in either species, which was interpreted to be the consequence of avoiding copper exposure. Although these data suggest that shallow-water taxa may be suitable ecotoxicological proxies for deep-sea taxa, differences in methodological and analytical approaches, and in sex and reproductive stage of experimental subjects, require caution in assessing the suitability of H. forskali as an ecotoxicological proxy for A. sp. Nonetheless, avoidance behaviour may have bioenergetic consequences that affect growth and/or reproductive output, potentially impacting fecundity and/or offspring fitness, and thus influencing source-sink dynamics and persistence of wider deep-sea populations. Copyright © 2017 Elsevier B.V. All rights reserved.
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Translations on Environmental Quality, Number 154.
1977-11-29
While some of the padi land is feared to have been permanently da- maged, tests indicate that some other parts could be cultivated again, if the...and Ecotoxicology at the offices of CETESB. According to F. Korte, who spoke on "Routes Followed by Chemical Substances in the Environment...professor began his presentation yesterday by establishing the param- eters for pollutants and then discussed the ecotoxicological effects on the
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Wang, Changyou; Wang, Ziyang; Zhang, Yong; Su, Rongguo
2017-05-24
The ecotoxicological effects of Ciprofloxacin hydrochloride (CIP) were tested on population densities of plankton assemblages consisting of two algae (Isochrysis galbana and Platymonas subcordiformis) and a rotifer (Brachionus plicatilis). The I. galbana showed a significant decrease in densities when concentrations of CIP were above 2.0 mg L -1 in single-species tests, while P. subcordiformis and B. plicatilis were stable in densities when CIP were less than10.0 mg L -1 . The equilibrium densities of I. galbana in community test increased with CIP concentrations after falling to a trough at 5.0 mg L -1 , showed a completely different pattern of P. subcordiformis which decreased with CIP concentrations after reaching a peak at 30.0 mg L -1 . The observed beneficial effect was a result of interspecies interactions of trophic cascade that buffered for more severe direct effects of toxicants. The community test-based NOEC of CIP (2.0 mg L -1 ), embodying the indirect effects, was different from the extrapolated one derived by single-species tests (0.5 mg L -1 ), but all lacked confidence interval. A CIP threshold concentration of obvious relevance to ecological interaction was calculated with a simplified plankton ecological model, achieving a value of 1.26 mg L -1 with a 95% bootstrapping confidence interval from 1.18 to 1.31 mg L -1 .
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Soil ecotoxicology in Brazil is taking its course.
Niva, Cintia Carla; Niemeyer, Julia Carina; Júnior, Flávio Manoel Rodrigues Da Silva; Nunes, Maria Edna Tenório; De Sousa, Danilo Lourenço; Aragão, Clara Wandenkolck Silva; Sautter, Klaus Dieter; Espindola, Evaldo Gaeta; Sousa, José Paulo; Römbke, Jörg
2016-06-01
Soil ecotoxicology has been motivated by the increasing global awareness on environmental issues. Northern Hemisphere has been the main driver of this science branch; however, the number and quality of contributions from the Southern Hemisphere are increasing quickly. In this case study, Brazil is taken as an example of how soil ecotoxicology has developed over the last 30 years. It starts with a brief historical overview depicting the main events on soil ecotoxicology in the country. Following, an overview on the Brazilian legislation related to soil ecotoxicology is given, covering regulations with prospective focus, mainly on the registration of pesticides. Regulations with retrospective focus in contaminated areas are also given. Then, an outline of the actors in soil ecotoxicology and examples of prospective ecotoxicological studies performed with soil organisms and plants are given by stressor groups: pesticides, pharmaceuticals, metals, and residues. Experiences from retrospective studies, mainly looking at the assessment of industrial sites, are also covered. Emphasis is given on methodological aspects, pointing to needed actions, mainly regarding the different biotic and abiotic conditions of a tropical country. Finally, the last session discusses how soil ecotoxicology could be improved in methodological adaptations as well as legal requirements.
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Distillation fraction-specific ecotoxicological evaluation of a paraffin-rich crude oil.
Erlacher, Elisabeth; Loibner, Andreas P; Kendler, Romana; Scherr, Kerstin E
2013-03-01
Crude oil is a complex mixture of petroleum hydrocarbons (PHC) with distinct chemical, physical and toxicological properties relevant for contaminated site risk assessment. Ecotoxicological effects of crude oil distillation fractions on luminescent bacteria (Vibrio fischeri), earthworms (Dendrobaena hortensis) and invertebrates (Heterocypris incongruens) were tested using two spiked soils and their elutriates. Fraction 2 (F2) had an equivalent carbon number (ECN) range of >10 to 16, and F3 from >16 to 39. F2 showed a substantially higher ecotoxicological effect than F3 for Vibrio and Dendrobaena. In contrast, severe inhibition of Heterocypris by the poorly soluble F3 is attributed to mechanical organ blockage. Immediate sequestration of PHC to the organic matter-rich soil effected reduced toxicity for all organisms. This study indicates that a more differentiated consideration (i) of PHC mixtures based on ECN range and (ii) of model soil properties employed for ecotoxicity testing should be included into PHC-contaminated site risk assessment. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Mebane, Christopher A.
2015-01-01
Criticisms of the uses of the no-observed-effect concentration (NOEC) and the lowest-observed-effect concentration (LOEC) and more generally the entire null hypothesis statistical testing scheme are hardly new or unique to the field of ecotoxicology [1-4]. Among the criticisms of NOECs and LOECs is that statistically similar LOECs (in terms of p value) can represent drastically different levels of effect. For instance, my colleagues and I found that a battery of chronic toxicity tests with different species and endpoints yielded LOECs with minimum detectable differences ranging from 3% to 48% reductions from controls [5].
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Oropesa, Ana Lourdes; Beltrán, Fernando Juan; Floro, António Miguel; Sagasti, Juan José Pérez; Palma, Patrícia
2018-01-01
The aim of the present study was to evaluate the ecotoxicological efficiency of two advanced ozonation processes (AOzPs), the catalytic ozonation (O 3 /TiO 2 ) and the photocatalytic ozonation (O 3 /TiO 2 /black light), in the remotion of carbamazepine. The ecotoxicological efficiency was assessed through the use of lethal and sublethal assays with species Vibrio fischeri and Daphnia magna. Results demonstrated that the AOzPs presented an efficiency of carbamazepine removal higher than 99% (carbamazepine < 2 μg/L) after 12 min of treatment. Relatively to ecotoxicological evaluation, application of acute assay to V. fischeri and chronic assay to D. magna allowed us to highlight that these technologies may form some transformation products that induce toxicity in the bacteria and the crustacean, once these organisms exposed to the undiluted solutions (100%) showed a decrease in the bioluminescence (vibrio) and end up dying before and during the first reproduction (daphnia). Despite that, when the chronic results obtained with the diluted solutions (50 and 25%; important to assess a more realistic scenario considering the dilution factor at the environment) were analyzed, no mortality at the mothers was observed. Compared to a carbamazepine solution (200 μg/L), diluted solutions improved of the reproduction parameters, and no toxic effects in the juvenoid system and in the embryonic development were observed. Relatively to the ecdysteroid effect of a carbamazepine solution (200 μg/L), only the photocatalytic ozonation treatment was able to remove the action of the drug. These results highlight the importance of complementing chemical analysis with ecotoxicological bioassays to assess the best technology to improve the surface water and effluent quality.
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Environmental chemistry and ecotoxicology: in greater demand than ever.
Scheringer, Martin
2017-01-01
Environmental chemistry and ecotoxicology have been losing support, resources, and recognition at universities for many years. What are the possible causes of this process? A first problem may be that the need for research and teaching in environmental chemistry and ecotoxicology is no longer seen because chemical pollution problems are considered as largely solved. Second, environmental chemistry and ecotoxicology may be seen as fields dominated by routine work and where there are not many interesting research questions left. A third part of the problem may be that other environmental impacts such as climate change are given higher priority than chemical pollution problems. Here, several cases are presented that illustrate the great demand for innovative research and teaching in environmental chemistry and ecotoxicology. It is crucial that environmental chemistry and ecotoxicology are rooted in academic science and are provided with sufficient equipment, resources, and prospects for development.
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Environmental Fate and Transport of a New Energetic Material, CL-20
2006-03-01
Microbiology M.Sc. Biochemistry M.Sc. Chemistry Ph.D. Chemistry Ph.D. Ecotoxicology M.Sc.A. Environmental Engineering B.Sc. Chemistry B.Sc...Determine enzymes responsible for initiating the degradation of CL-20. 5. Conduct a battery of ecotoxicological tests to determine the toxic effects of...chrysosporium. The strain ATCC 24725 was maintained on Yeast Peptone Dextrose (YPD) plates and was cultivated in the modified Kirk’s nitrogen- limited medium (pH
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Environmental risk assessment of pharmaceutical drug substances--conceptual considerations.
Länge, Reinhard; Dietrich, Daniel
2002-05-10
Drugs, i.e. active ingredients of human medicinal products, may be introduced into the environment after use in patients by sewage effluent pathways and consequently are detected at low concentrations in sewage effluents and in surface waters. Legal requirements in a number of geographical regions (Europe, US, and intended in Canada) demand environmental risk assessments (ERA) for new drug substances. Existing regulatory concepts of ERA are based initially on a set of short-term ecotoxicological studies in three to four different species, environmental behavior and the application of assessment factors to correct for the ERA inherent uncertainty. Based on theoretical considerations and the experience with a very limited, but well investigated, number of examples while considering that drugs are highly biologically active compounds, the appropriateness of this risk assessment procedure for all drug substances might be questioned. Indeed, e.g. long-term effects may occur at much lower concentrations and follow different toxicodynamic mechanism than extrapolated from short-term studies., In such cases, the application of assessment factors for deriving chronic no-observed effect concentration (NOECs) appears to be problematic. Although long-term tests with a variety of organisms would provide a complete database for the evaluation of the environmental risks, this is unachievable for all drugs due to time, money and animal welfare constraints. In order to avoid unnecessary testing, a concept is presented, which makes use of pharmacological and toxicological, as well as pharmaco- and toxicokinetic information derived from mammals during drug substance development. Useful data for adoption in a case-by-case testing strategy can be obtained by evaluating (a) the pharmacological activity, which indicates specific targets in mammalian species and may allow for an analysis, whether a similar target is available in aquatic species; (b) the mammalian toxicity, which may indicate, which targets are most susceptible to adverse effects; (c) the difference between acute and chronic effects in mammals, since the magnitude of this difference may indicate, whether long-term effects are expected at significantly lower levels than acute effects; (d) the (pharmacologically and toxicologically) effective plasma levels in mammalian test organisms, which may be compared with the relevant exposure scenario for the environment. Additionally, activity classes of compounds may be established based on experience with specific substances, in order to develop an appropriate test strategy. The above preliminary considerations should support decisions on the selection of candidate substances for chronic effects studies and for the appropriate selection of test species and endpoints to monitor. Generally, ecologically relevant endpoints such as impairment of growth, development and reproduction should be used to assess the ecotoxicologic effects.
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Connon, Richard E.; Geist, Juergen; Werner, Inge
2012-01-01
Ecotoxicology faces the challenge of assessing and predicting the effects of an increasing number of chemical stressors on aquatic species and ecosystems. Herein we review currently applied tools in ecological risk assessment, combining information on exposure with expected biological effects or environmental water quality standards; currently applied effect-based tools are presented based on whether exposure occurs in a controlled laboratory environment or in the field. With increasing ecological relevance the reproducibility, specificity and thus suitability for standardisation of methods tends to diminish. We discuss the use of biomarkers in ecotoxicology including ecotoxicogenomics-based endpoints, which are becoming increasingly important for the detection of sublethal effects. Carefully selected sets of biomarkers allow an assessment of exposure to and effects of toxic chemicals, as well as the health status of organisms and, when combined with chemical analysis, identification of toxicant(s). The promising concept of “adverse outcome pathways (AOP)” links mechanistic responses on the cellular level with whole organism, population, community and potentially ecosystem effects and services. For most toxic mechanisms, however, practical application of AOPs will require more information and the identification of key links between responses, as well as key indicators, at different levels of biological organization, ecosystem functioning and ecosystem services. PMID:23112741
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Incorporating evolutionary insights to improve ecotoxicology for freshwater species
Brady, Steven P.; Richardson, Jonathan L.; Kunz, Bethany K.
2017-01-01
Ecotoxicological studies have provided extensive insights into the lethal and sublethal effects of environmental contaminants. These insights are critical for environmental regulatory frameworks, which rely on knowledge of toxicity for developing policies to manage contaminants. While varied approaches have been applied to ecotoxicological questions, perspectives related to the evolutionary history of focal species or populations have received little consideration. Here, we evaluate chloride toxicity from the perspectives of both macroevolution and contemporary evolution. First, by mapping chloride toxicity values derived from the literature onto a phylogeny of macroinvertebrates, fish, and amphibians, we tested whether macroevolutionary relationships across species and taxa are predictive of chloride tolerance. Next, we conducted chloride exposure tests for two amphibian species to assess whether potential contemporary evolutionary change associated with environmental chloride contamination influences chloride tolerance across local populations. We show that explicitly evaluating both macroevolution and contemporary evolution can provide important and even qualitatively different insights from those obtained via traditional ecotoxicological studies. While macroevolutionary perspectives can help forecast toxicological end points for species with untested sensitivities, contemporary evolutionary perspectives demonstrate the need to consider the environmental context of exposed populations when measuring toxicity. Accounting for divergence among populations of interest can provide more accurate and relevant information related to the sensitivity of populations that may be evolving in response to selection from contaminant exposure. Our data show that approaches accounting for and specifically examining variation among natural populations should become standard practice in ecotoxicology.
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Gooré Bi, Eustache; Monette, Frederic; Gasperi, Johnny; Perrodin, Yves
2015-03-01
Very few tools are available for assessing the impact of combined sewer overflows (CSOs) on receiving aquatic environments. The main goal of the study was to assess the ecotoxicological risk of CSOs for a surface aquatic ecosystem using a coupled "substance and bioassay" approach. Wastewater samples from the city of Longueuil, Canada CSO were collected for various rainfall events during one summer season and analyzed for a large panel of substances (n = 116). Four bioassays were also conducted on representative organisms of surface aquatic systems (Pimephales promelas, Ceriodaphnia dubia, Daphnia magna, and Oncorhynchus mykiss). The analytical data did not reveal any ecotoxicological risk for St. Lawrence River organisms, mainly due to strong effluent dilution. However, the substance approach showed that, because of their contribution to the ecotoxicological hazard posed by the effluent, total phosphorus (Ptot), aluminum (Al), total residual chlorine, chromium (Cr), copper (Cu), pyrene, ammonia (N-NH4 (+)), lead (Pb), and zinc (Zn) require more targeted monitoring. While chronic ecotoxicity tests revealed a potential impact of CSO discharges on P. promelas and C. dubia, acute toxicity tests did not show any effect on D. magna or O. mykiss, thus underscoring the importance of chronic toxicity tests as part of efforts aimed at characterizing effluent toxicity. Ultimately, the study leads to the conclusion that the coupled "substance and bioassay" approach is a reliable and robust method for assessing the ecotoxicological risk associated with complex discharges such as CSOs.
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Pesce, Stéphane; Perceval, Olivier; Bonnineau, Chloé; Casado-Martinez, Carmen; Dabrin, Aymeric; Lyautey, Emilie; Naffrechoux, Emmanuel; Ferrari, Benoit J D
2018-01-01
The first French-Swiss workshop on ecotoxicology of freshwater sediment communities was co-organized by the French Research Institute of Science and Technology for Environment and Agriculture (Irstea) and the Swiss Centre for Applied Ecotoxicology (Ecotox Centre EAWAG-EPFL) in Villié-Morgon (Beaujolais Region, France) on April 27-28, 2017. The workshop brought together scientists working in different fields of expertise (ecotoxicologists, ecologists, environmental chemists…), environmental stakeholder groups and managers, as well as economic players (start-ups and consultancies) to better connect research needs of potential end-users with research outputs. The objectives of this workshop were (i) to establish the state of the art of research in the characterization of sediment contamination and in the evaluation of the effects on sediment-associated biological communities and ecosystem functioning and (ii) to give an overview of the French and Swiss regulations dealing with the assessment of contaminated sediments in freshwater ecosystems. The ultimate goal was to collectively identify research needs and knowledge gaps, as well as to highlight ways to improve the ecotoxicological assessment of sediments in freshwater environments by further considering the structure and functions of associated microbial and invertebrate communities.
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Prasse, Carsten; Stalter, Daniel; Schulte-Oehlmann, Ulrike; Oehlmann, Jörg; Ternes, Thomas A
2015-12-15
The knowledge we have gained in recent years on the presence and effects of compounds discharged by wastewater treatment plants (WWTPs) brings us to a point where we must question the appropriateness of current water quality evaluation methodologies. An increasing number of anthropogenic chemicals is detected in treated wastewater and there is increasing evidence of adverse environmental effects related to WWTP discharges. It has thus become clear that new strategies are needed to assess overall quality of conventional and advanced treated wastewaters. There is an urgent need for multidisciplinary approaches combining expertise from engineering, analytical and environmental chemistry, (eco)toxicology, and microbiology. This review summarizes the current approaches used to assess treated wastewater quality from the chemical and ecotoxicological perspective. Discussed chemical approaches include target, non-target and suspect analysis, sum parameters, identification and monitoring of transformation products, computational modeling as well as effect directed analysis and toxicity identification evaluation. The discussed ecotoxicological methodologies encompass in vitro testing (cytotoxicity, genotoxicity, mutagenicity, endocrine disruption, adaptive stress response activation, toxicogenomics) and in vivo tests (single and multi species, biomonitoring). We critically discuss the benefits and limitations of the different methodologies reviewed. Additionally, we provide an overview of the current state of research regarding the chemical and ecotoxicological evaluation of conventional as well as the most widely used advanced wastewater treatment technologies, i.e., ozonation, advanced oxidation processes, chlorination, activated carbon, and membrane filtration. In particular, possible directions for future research activities in this area are provided. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Drug residues in urban water: A database for ecotoxicological risk management.
Destrieux, Doriane; Laurent, François; Budzinski, Hélène; Pedelucq, Julie; Vervier, Philippe; Gerino, Magali
2017-12-31
Human-use drug residues (DR) are only partially eliminated by waste water treatment plants (WWTPs), so that residual amounts can reach natural waters and cause environmental hazards. In order to properly manage these hazards in the aquatic environment, a database is made available that integrates the concentration ranges for DR, which cause adverse effects for aquatic organisms, and the temporal variations of the ecotoxicological risks. To implement this database for the ecotoxicological risk assessment (ERA database), the required information for each DR is the predicted no effect concentrations (PNECs), along with the predicted environmental concentrations (PECs). The risk assessment is based on the ratio between the PNECs and the PECs. Adverse effect data or PNECs have been found in the publicly available literature for 45 substances. These ecotoxicity test data have been extracted from 125 different sources. This ERA database contains 1157 adverse effect data and 287 PNECs. The efficiency of this ERA database was tested with a data set coming from a simultaneous survey of WWTPs and the natural environment. In this data set, 26 DR were searched for in two WWTPs and in the river. On five sampling dates, concentrations measured in the river for 10 DR could pose environmental problems of which 7 were measured only downstream of WWTP outlets. From scientific literature and measurements, data implementation with unit homogenisation in a single database facilitates the actual ecotoxicological risk assessment, and may be useful for further risk coming from data arising from the future field survey. Moreover, the accumulation of a large ecotoxicity data set in a single database should not only improve knowledge of higher risk molecules but also supply an objective tool to help the rapid and efficient evaluation of the risk. Copyright © 2017 Elsevier B.V. All rights reserved.
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Hudspith, M; Reichelt-Brushett, Amanda; Harrison, Peter L
2017-03-01
Significant amounts of trace metals have been released into both nearshore and deep sea environments in recent years, resulting in increased concentrations that can be toxic to marine organisms. Trace metals can negatively affect external fertilization processes in marine broadcast spawners and may cause a reduction in fertilization success at elevated concentrations. Due to its sensitivity and ecological importance, fertilization success has been widely used as a toxicity endpoint in ecotoxicological testing, which is an important method of evaluating the toxicity of contaminants for management planning. Ecotoxicological data regarding fertilization success are available across the major marine phyla, but there remain uncertainties that impair our ability to confidently interpret and analyse these data. At present, the cellular and biochemical events underlying trace metal toxicity in external fertilization are not known. Metal behavior and speciation play an important role in bioavailability and toxicity but are often overlooked, and disparities in experimental designs between studies limit the degree to which results can be synthesised and compared to those of other relevant species. We reviewed all available literature covering cellular toxicity mechanisms, metal toxicities and speciation, and differences in methodologies between studies. We conclude that the concept of metal toxicity should be approached in a more holistic manner that involves elucidating toxicity mechanisms, improving the understanding of metal behavior and speciation on bioavailability and toxicity, and standardizing the fertilization assay methods among different groups of organisms. We identify opportunities to improve the fertilization assay that will allow robust critical and comparative analysis between species and their sensitivities to trace metals during external fertilization, and enable data to be more readily extrapolated to field conditions. Copyright © 2017 Elsevier B.V. All rights reserved.
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Toward a unified approach to dose-response modeling in ecotoxicology.
Ritz, Christian
2010-01-01
This study reviews dose-response models that are used in ecotoxicology. The focus lies on clarification of differences and similarities between models, and as a side effect, their different guises in ecotoxicology are unravelled. A look at frequently used dose-response models reveals major discrepancies, among other things in naming conventions. Therefore, there is a need for a unified view on dose-response modeling in order to improve the understanding of it and to facilitate communication and comparison of findings across studies, thus realizing its full potential. This study attempts to establish a general framework that encompasses most dose-response models that are of interest to ecotoxicologists in practice. The framework includes commonly used models such as the log-logistic and Weibull models, but also features entire suites of models as found in various guidance documents. An outline on how the proposed framework can be implemented in statistical software systems is also provided.
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An ecotoxicological characterization of nanocrystalline cellulose (NCC).
Kovacs, Tibor; Naish, Valerie; O'Connor, Brian; Blaise, Christian; Gagné, Francois; Hall, Lauren; Trudeau, Vance; Martel, Pierre
2010-09-01
The pulp and paper industry in Canada is developing technology for the production and use of nanocrystalline cellulose (NCC). A key component of the developmental work is an assessment of potential environmental risks. Towards this goal, NCC samples as well as carboxyl methyl cellulose (CMC), a surrogate of the parent cellulosic material, were subjected to an ecotoxicological evaluation. This involved toxicity tests with rainbow trout hepatocytes and nine aquatic species. The hepatocytes were most sensitive (EC20s between 10 and 200 mg/l) to NCC, although neither NCC nor CMC caused genotoxicity. In tests with the nine species, NCC affected the reproduction of the fathead minnow at (IC25) 0.29 g/l, but no other effects on endpoints such as survival and growth occurred in the other species at concentrations below 1 g/l, which was comparable to CMC. Based on this ecotoxicological characterization, NCC was found to have low toxicity potential and environmental risk.
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Mottier, Antoine; Mouchet, Florence; Pinelli, Éric; Gauthier, Laury; Flahaut, Emmanuel
2017-08-01
Nano-ecotoxicology is an emerging science which aims to assess the environmental effect of nanotechnologies. The development of this particular aspect of ecotoxicology was made necessary in order to evaluate the potential impact of recently produced and used materials: nanoparticles (NPs). Among all the types of NPs, carbon nanoparticles (CNPs) especially draw attention giving the increasing number of applications and integration into consumer products. However the potential impacts of CNPs in the environment remain poorly known. This review aims to point out the critical issues and aspects that will govern the toxicity of CNPs in the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Terzic, Senka; Udikovic-Kolic, Nikolina; Jurina, Tamara; Krizman-Matasic, Ivona; Senta, Ivan; Mihaljevic, Ivan; Loncar, Jovica; Smital, Tvrtko; Ahel, Marijan
2018-05-05
The biotransformation of three prominent macrolide antibiotics (azithromycin, clarithromycin and erythromycin) by an activated sludge culture, which was adapted to high concentrations of azithromycin (10 mg/L) was investigated. The study included determination of removal kinetics of the parent compounds, identification of their major biotransformation products (TPs) and assessment of ecotoxicological effects of biotransformation. The chemical analyses were performed by ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry, which enabled a tentative identification of TPs formed during the experiments. The ecotoxicological evaluation included two end-points, residual antibiotic activity and toxicity to freshwater algae. The enriched activated sludge culture was capable of degrading all studied macrolide compounds with high removal efficiencies (>99%) of the parent compounds at elevated concentrations (10 mg/L). The elimination of all three macrolide antibiotics was associated with the formation of different TPs, including several novel compounds previously unreported in the literature. Some of the TPs were rather abundant and contributed significantly to the overall mass balance at the end of the biodegradation experiments. Biodegradation of all investigated macrolides was associated with a pronounced reduction of the residual antibiotic activity and algal toxicity, indicating a rather positive ecotoxicological outcome of the biotransformation processes achieved by the enriched sludge culture. Copyright © 2018 Elsevier B.V. All rights reserved.
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Industrial ecotoxicology "acid rain".
Astolfi, E; Gotelli, C; Higa, J
1986-01-01
The acid rain phenomenon was studied in the province of Cordoba, Argentina. This study, based on a previously outlined framework, determined the anthropogenic origin of the low pH due to the presence of industrial hydrochloric acid wastage. This industrial ecotoxicological phenomenon seriously affected the forest wealth, causing a great defoliation of trees and shrubs, with a lower effect on crops. A survey on its effects on human beings has not been carried out, but considering the corrosion caused to different metals and its denouncing biocide effect on plants and animals, we should expect to find some kind of harm to the health of the workers involved or others engaged in farming, and even to those who are far away from the polluting agent.
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Brown, Alastair; Thatje, Sven; Hauton, Chris
2017-09-05
Mineral prospecting in the deep sea is increasing, promoting concern regarding potential ecotoxicological impacts on deep-sea fauna. Technological difficulties in assessing toxicity in deep-sea species has promoted interest in developing shallow-water ecotoxicological proxy species. However, it is unclear how the low temperature and high hydrostatic pressure prevalent in the deep sea affect toxicity, and whether adaptation to deep-sea environmental conditions moderates any effects of these factors. To address these uncertainties we assessed the effects of temperature and hydrostatic pressure on lethal and sublethal (respiration rate, antioxidant enzyme activity) toxicity in acute (96 h) copper and cadmium exposures, using the shallow-water ecophysiological model organism Palaemon varians. Low temperature reduced toxicity in both metals, but reduced cadmium toxicity significantly more. In contrast, elevated hydrostatic pressure increased copper toxicity, but did not affect cadmium toxicity. The synergistic interaction between copper and cadmium was not affected by low temperature, but high hydrostatic pressure significantly enhanced the synergism. Differential environmental effects on toxicity suggest different mechanisms of action for copper and cadmium, and highlight that mechanistic understanding of toxicity is fundamental to predicting environmental effects on toxicity. Although results infer that sensitivity to toxicants differs across biogeographic ranges, shallow-water species may be suitable ecotoxicological proxies for deep-sea species, dependent on adaptation to habitats with similar environmental variability.
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Peterson, Elizabeth K.; Buchwalter, David B.; Kerby, Jacob L.; LeFauve, Matthew K.; Varian-Ramos, Claire W.
2017-01-01
Abstract The fields of behavioral ecology, conservation science, and environmental toxicology individually aim to protect and manage the conservation of wildlife in response to anthropogenic stressors, including widespread anthropogenic pollution. Although great emphasis in the field of toxicology has been placed on understanding how single pollutants affect survival, a comprehensive, interdisciplinary approach that includes behavioral ecology is essential to address how anthropogenic compounds are a risk for the survival of species and populations in an increasingly polluted world. We provide an integrative framework for behavioral ecotoxicology using Tinbergen’s four postulates (causation and mechanism, development and ontogeny, function and fitness, and evolutionary history and phylogenetic patterns). The aims of this review are: 1) to promote an integrative view and re-define the field of integrative behavioral ecotoxicology; 2) to demonstrate how studying ecotoxicology can promote behavior research; and 3) to identify areas of behavioral ecotoxicology that require further attention to promote the integration and growth of the field. PMID:29491976
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Faimali, Marco; Gambardella, Chiara; Costa, Elisa; Piazza, Veronica; Morgana, Silvia; Estévez-Calvar, Noelia; Garaventa, Francesca
2017-07-01
Behavioral responses of aquatic organisms have received much less attention than developmental or reproductive ones due to the scarce presence of user-friendly tools for their acquisition. The technological development of data acquisition systems for quantifying behavior in the aquatic environment and the increase of studies on the understanding the relationship between the behavior of aquatic organisms and the physiological/ecological activities have generated renewed interest in using behavioral responses also in marine ecotoxicology. Recent reviews on freshwater environment show that behavioral end-points are comparatively fast and sensitive, and warrant further attention as tools for assessing the toxicological effects of environmental contaminants. In this mini-review, we perform a systematic analysis of the most recent works that have used marine invertebrate swimming alteration as behavioral end-point in ecotoxicological studies by assessing the differences between behavioral and acute responses in a wide range of species, in order to compare their sensitivity. Copyright © 2016. Published by Elsevier Ltd.
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Maximum entropy estimation of a Benzene contaminated plume using ecotoxicological assays.
Wahyudi, Agung; Bartzke, Mariana; Küster, Eberhard; Bogaert, Patrick
2013-01-01
Ecotoxicological bioassays, e.g. based on Danio rerio teratogenicity (DarT) or the acute luminescence inhibition with Vibrio fischeri, could potentially lead to significant benefits for detecting on site contaminations on qualitative or semi-quantitative bases. The aim was to use the observed effects of two ecotoxicological assays for estimating the extent of a Benzene groundwater contamination plume. We used a Maximum Entropy (MaxEnt) method to rebuild a bivariate probability table that links the observed toxicity from the bioassays with Benzene concentrations. Compared with direct mapping of the contamination plume as obtained from groundwater samples, the MaxEnt concentration map exhibits on average slightly higher concentrations though the global pattern is close to it. This suggest MaxEnt is a valuable method to build a relationship between quantitative data, e.g. contaminant concentrations, and more qualitative or indirect measurements, in a spatial mapping framework, which is especially useful when clear quantitative relation is not at hand. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Besse, Jean-Philippe; Latour, Jean-François; Garric, Jeanne
2012-02-01
This study considers the implications and research needs arising from anticancer (also referred to as antineoplastic) drugs being released into the aquatic environment, for the entire therapeutic classes used: cytotoxic, cytostatic and endocrine therapy drugs. A categorization approach, based on French consumption amounts, allowed to highlight parent molecules and several metabolites on which further occurrence and ecotoxicological studies should be conducted. Investigations of consumption trends at a national and a local scale show an increase in the use of anticancer drugs between 2004 and 2008, thus leading to increased levels released in the environment. It therefore appears necessary to continue surveying their presence in surface waters and in wastewater treatment plant (WWTP) effluents. Furthermore, due to the rise of anticancer home treatments, most of the prescribed molecules are now available in town pharmacies. Consequently, hospital effluents are no longer the main expected entry route of anticancer drugs into the aquatic environment. Concerning ecotoxicological risks, current knowledge remains insufficient to support a definitive conclusion. Risk posed by cytotoxic molecules is still not well documented and it is not possible to conclude on their long-term effects on non-target organisms. To date, ecotoxicological effects have been assessed using standardized or in vitro assays. Such tests however may not be suitable for anticancer drugs, and further work should focus on full-life cycle or even multigenerational tests. Environmental significance (i.e. occurrence and effects) of cytostatics (protein kinases inhibitors and monoclonal antibodies), if any, is not documented. Protein kinases inhibitors, in particular, deserve further investigation due to their universal mode of action. Finally, concerning endocrine therapy drugs, molecules such as antiestrogen Tamoxifen and its active metabolites, could be of concern. Overall, to accurately assess the ecotoxicological risk of anticancer drugs, we discuss the need to break away from tests on isolated molecules and to test effects of mixtures at the low ng.l(-1) range. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Ecotoxicology of Amphibians and Reptiles
2000-01-01
For many years, ecological research on amphibians and reptiles has lagged behind that of other vertebrates such as fishes, birds, and mammals, despite the known importance of these animals in their environments. The lack of study has been particularly acute in the he area of ecotoxicology where the number of published scientific papers is a fraction of that found for the other vertebrate classes. Recently, scientists have become aware of severe crises among amphibian populations, including unexplained and sudden extinctions, worldwide declines, and hideous malformations. In many of these instances, contaminants have been listed as probable contributors. Data on the effects of contaminants on reptiles are so depauperate that even the most elementary interpretations are difficult. This state-of-the-science review and synthesis of amphibian and reptile ecotoxicology demonstrates the inter-relationships among distribution, ecology, physiology, and contaminant exposure, and interprets these topics as they pertain to comparative toxicity, population declines, malformations, and risk assessment . In this way, the book identifies and serves as a basis for the most pressing research needs in the coming years. The editors have invited 27 other internationally respected experts to examine the state of existing data in specific areas, interpret it in light of current problems, and identify research gaps and needs. Through its emphasis on recent research, extensive reviews and synthesis, Ecotoxicology of Amphibians and Reptiles will remain a definitive reference work well into the new century.
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Nagel, Roland
2002-01-01
The acute fish test is an animal test whose ecotoxicological relevance is worthy of discussion. The primary aim of protection in ecotoxicology is the population and not the individual. Furthermore the concentration of pollutants in the environment is normally not in the lethal range. Therefore the acute fish test covers solely the situation after chemical spills. Nevertheless, acute fish toxicity data still belong to the base set used for the assessment of chemicals. The embryo test with the zebrafish Danio rerio (DarT) is recommended as a substitute for the acute fish test. For validation an international laboratory comparison test was carried out. A summary of the results is presented in this paper. Based on the promising results of testing chemicals and waste water the test design was validated by the DIN-working group "7.6 Fischei-Test". A normed test guideline for testing waste water with fish is available. The test duration is short (48 h) and within the test different toxicological endpoints can be examined. Endpoints from the embryo test are suitable for QSAR-studies. Besides the use in ecotoxicology the introduction as a toxicological model was investigated. Disturbance of pigmentation and effects on the frequency of heart-beat were examined. A further important application is testing of teratogenic chemicals. Based on the results DarT could be a screening test within preclinical studies.
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Allee effect in polar bears: a potential consequence of polychlorinated biphenyl contamination.
Pavlova, Viola; Nabe-Nielsen, Jacob; Dietz, Rune; Sonne, Christian; Grimm, Volker
2016-11-30
Polar bears (Ursus maritimus) from East Greenland and Svalbard exhibited very high concentrations of polychlorinated biphenyls (PCBs) in the 1980s and 1990s. In Svalbard, slow population growth during that period was suspected to be linked to PCB contamination. In this case study, we explored how PCBs could have impacted polar bear population growth and/or male reproductive success in Svalbard during the mid-1990s by reducing the fertility of contaminated males. A dose-response relationship linking the effects of PCBs to male polar bear fertility was extrapolated from studies of the effects of PCBs on sperm quality in rodents. Based on this relationship, an individual-based model of bear interactions during the breeding season predicted fertilization success under alternative assumptions regarding male-male competition for females. Contamination reduced pregnancy rates by decreasing the availability of fertile males, thus triggering a mate-finding Allee effect, particularly when male-male competition for females was limited or when infertile males were able to compete with fertile males for females. Comparisons of our model predictions on age-dependent reproductive success of males with published empirical observations revealed that the low representation of 10-14-year-old males among breeding males documented in Svalbard in mid-1990s could have resulted from PCB contamination. We conclude that contamination-related male infertility may lead to a reduction in population growth via an Allee effect. The magnitude of the effect is largely dependent on the population-specific mating system. In eco-toxicological risk assessments, appropriate consideration should therefore be given to negative effects of contaminants on male fertility and male mating behaviour. © 2016 The Author(s).
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Allee effect in polar bears: a potential consequence of polychlorinated biphenyl contamination
Nabe-Nielsen, Jacob; Dietz, Rune; Sonne, Christian; Grimm, Volker
2016-01-01
Polar bears (Ursus maritimus) from East Greenland and Svalbard exhibited very high concentrations of polychlorinated biphenyls (PCBs) in the 1980s and 1990s. In Svalbard, slow population growth during that period was suspected to be linked to PCB contamination. In this case study, we explored how PCBs could have impacted polar bear population growth and/or male reproductive success in Svalbard during the mid-1990s by reducing the fertility of contaminated males. A dose–response relationship linking the effects of PCBs to male polar bear fertility was extrapolated from studies of the effects of PCBs on sperm quality in rodents. Based on this relationship, an individual-based model of bear interactions during the breeding season predicted fertilization success under alternative assumptions regarding male–male competition for females. Contamination reduced pregnancy rates by decreasing the availability of fertile males, thus triggering a mate-finding Allee effect, particularly when male–male competition for females was limited or when infertile males were able to compete with fertile males for females. Comparisons of our model predictions on age-dependent reproductive success of males with published empirical observations revealed that the low representation of 10–14-year-old males among breeding males documented in Svalbard in mid-1990s could have resulted from PCB contamination. We conclude that contamination-related male infertility may lead to a reduction in population growth via an Allee effect. The magnitude of the effect is largely dependent on the population-specific mating system. In eco-toxicological risk assessments, appropriate consideration should therefore be given to negative effects of contaminants on male fertility and male mating behaviour. PMID:27903868
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Invertebrates in testing of environmental chemicals: are they alternatives?
Lagadic, L; Caquet, T
1998-01-01
An enlarged interpretation of alternatives in toxicology testing includes the replacement of one animal species with another, preferably a nonmammalian species. This paper reviews the potential of invertebrates in testing environmental chemicals and provides evidence of their usefulness in alternative testing methodologies. The first part of this review addresses the use of invertebrates in laboratory toxicology testing. Problems in extrapolating results obtained in invertebrates to those obtained from vertebrates are noted, suggesting that invertebrates can essentially be used in addition to rather than as replacements for vertebrates in laboratory toxicity tests. However, evaluation of the ecologic impact of environmental chemicals must include defining end points that may frequently differ from those classically used in biomedical research. In this context, alternative approaches using invertebrates may be more pertinent. The second part of the review therefore focuses on the use of invertebrates in situ to assess the environmental impact of pollutants. Advantages of invertebrates in ecotoxicologic investigation are presented for their usefulness for seeking mechanistic links between effects occurring at the individual level and consequences for higher levels of biologic organization (e.g., population and community). In the end, it is considered that replacement of vertebrates by invertebrates in ecotoxicity testing is likely to become a reality when basic knowledge of metabolic, physiologic, and developmental patterns in the latter will be sufficient to assess the effect of a given chemical through end points that could be different between invertebrates and vertebrates. PMID:9599707
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Assessing the Ecotoxicologic Hazards of a Pandemic Influenza Medical Response
Colizza, Vittoria; Schmitt, Heike; Andrews, Johanna; Balcan, Duygu; Huang, Wei E.; Keller, Virginie D.J.; Vespignani, Alessandro; Williams, Richard J.
2011-01-01
Background: The global public health community has closely monitored the unfolding of the 2009 H1N1 influenza pandemic to best mitigate its impact on society. However, little attention has been given to the impact of this response on the environment. Antivirals and antibiotics prescribed to treat influenza are excreted into wastewater in a biologically active form, which presents a new and potentially significant ecotoxicologic challenge to microorganisms responsible for wastewater nutrient removal in wastewater treatment plants (WWTPs) and receiving rivers. Objectives: We assessed the ecotoxicologic risks of a pandemic influenza medical response. Methods: To evaluate this risk, we coupled a global spatially structured epidemic model that simulates the quantities of antivirals and antibiotics used during an influenza pandemic of varying severity and a water quality model applied to the Thames catchment to determine predicted environmental concentrations. An additional model was then used to assess the effects of antibiotics on microorganisms in WWTPs and rivers. Results: Consistent with expectations, our model projected a mild pandemic to exhibit a negligible ecotoxicologic hazard. In a moderate and severe pandemic, we projected WWTP toxicity to vary between 0–14% and 5–32% potentially affected fraction (PAF), respectively, and river toxicity to vary between 0–14% and 0–30% PAF, respectively, where PAF is the fraction of microbial species predicted to be growth inhibited (lower and upper 95% reference range). Conclusions: The current medical response to pandemic influenza might result in the discharge of insufficiently treated wastewater into receiving rivers, thereby increasing the risk of eutrophication and contamination of drinking water abstraction points. Widespread drugs in the environment could hasten the generation of drug resistance. Our results highlight the need for empirical data on the effects of antibiotics and antiviral medications on WWTPs and freshwater ecotoxicity. PMID:21367688
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Assessing the ecotoxicologic hazards of a pandemic influenza medical response.
Singer, Andrew C; Colizza, Vittoria; Schmitt, Heike; Andrews, Johanna; Balcan, Duygu; Huang, Wei E; Keller, Virginie D J; Vespignani, Alessandro; Williams, Richard J
2011-08-01
The global public health community has closely monitored the unfolding of the 2009 H1N1 influenza pandemic to best mitigate its impact on society. However, little attention has been given to the impact of this response on the environment. Antivirals and antibiotics prescribed to treat influenza are excreted into wastewater in a biologically active form, which presents a new and potentially significant ecotoxicologic challenge to microorganisms responsible for wastewater nutrient removal in wastewater treatment plants (WWTPs) and receiving rivers. We assessed the ecotoxicologic risks of a pandemic influenza medical response. To evaluate this risk, we coupled a global spatially structured epidemic model that simulates the quantities of antivirals and antibiotics used during an influenza pandemic of varying severity and a water quality model applied to the Thames catchment to determine predicted environmental concentrations. An additional model was then used to assess the effects of antibiotics on microorganisms in WWTPs and rivers. Consistent with expectations, our model projected a mild pandemic to exhibit a negligible ecotoxicologic hazard. In a moderate and severe pandemic, we projected WWTP toxicity to vary between 0-14% and 5-32% potentially affected fraction (PAF), respectively, and river toxicity to vary between 0-14% and 0-30% PAF, respectively, where PAF is the fraction of microbial species predicted to be growth inhibited (lower and upper 95% reference range). The current medical response to pandemic influenza might result in the discharge of insufficiently treated wastewater into receiving rivers, thereby increasing the risk of eutrophication and contamination of drinking water abstraction points. Widespread drugs in the environment could hasten the generation of drug resistance. Our results highlight the need for empirical data on the effects of antibiotics and antiviral medications on WWTPs and freshwater ecotoxicity.
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Rodea-Palomares, Ismael; González-Pleiter, Miguel; Martín-Betancor, Keila; Rosal, Roberto; Fernández-Piñas, Francisca
2015-01-01
Understanding the effects of exposure to chemical mixtures is a common goal of pharmacology and ecotoxicology. In risk assessment-oriented ecotoxicology, defining the scope of application of additivity models has received utmost attention in the last 20 years, since they potentially allow one to predict the effect of any chemical mixture relying on individual chemical information only. The gold standard for additivity in ecotoxicology has demonstrated to be Loewe additivity which originated the so-called Concentration Addition (CA) additivity model. In pharmacology, the search for interactions or deviations from additivity (synergism and antagonism) has similarly captured the attention of researchers over the last 20 years and has resulted in the definition and application of the Combination Index (CI) Theorem. CI is based on Loewe additivity, but focused on the identification and quantification of synergism and antagonism. Despite additive models demonstrating a surprisingly good predictive power in chemical mixture risk assessment, concerns still exist due to the occurrence of unpredictable synergism or antagonism in certain experimental situations. In the present work, we summarize the parallel history of development of CA, IA, and CI models. We also summarize the applicability of these concepts in ecotoxicology and how their information may be integrated, as well as the possibility of prediction of synergism. Inside the box, the main question remaining is whether it is worthy to consider departures from additivity in mixture risk assessment and how to predict interactions among certain mixture components. Outside the box, the main question is whether the results observed under the experimental constraints imposed by fractional approaches are a de fide reflection of what it would be expected from chemical mixtures in real world circumstances. PMID:29051468
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Methodology for the Assessment of the Ecotoxicological Potential of Construction Materials
Rodrigues, Patrícia; Silvestre, José D.; Flores-Colen, Inês; Viegas, Cristina A.; de Brito, Jorge; Kurad, Rawaz; Demertzi, Martha
2017-01-01
Innovation in construction materials (CM) implies changing their composition by incorporating raw materials, usually non-traditional ones, which confer the desired characteristics. However, this practice may have unknown risks. This paper discusses the ecotoxicological potential associated with raw and construction materials, and proposes and applies a methodology for the assessment of their ecotoxicological potential. This methodology is based on existing laws, such as Regulation (European Commission) No. 1907/2006 (REACH—Registration, Evaluation, Authorization and Restriction of Chemicals) and Regulation (European Commission) No. 1272/2008 (CLP—Classification, Labelling and Packaging). Its application and validation showed that raw material without clear evidence of ecotoxicological potential, but with some ability to release chemicals, can lead to the formulation of a CM with a slightly lower hazardousness in terms of chemical characterization despite a slightly higher ecotoxicological potential than the raw materials. The proposed methodology can be a useful tool for the development and manufacturing of products and the design choice of the most appropriate CM, aiming at the reduction of their environmental impact and contributing to construction sustainability. PMID:28773011
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Scott-Fordsmand, J J; Weeks, J M
2000-01-01
Earthworms are believed to be so-called key species within ecosystems and are often exposed to a wide range of anthropogenic compounds released to the terrestrial environment. As a consequence, they may suffer from the toxicity of these compounds. For these and other reasons, earthworms have been used extensively in ecotoxicological studies. In recent years the use of other biological responses (biomarkers) to estimate either exposure or resultant effects of chemicals has received increased attention. Biomarkers address the question of bioavailability by only responding to the bioactive fraction. They may incorporate effects following exposure to a mixture of chemicals. Biomarkers may also reduce extrapolation of results from the laboratory to the field, as they may be applicable under both conditions. The present review has drawn together current knowledge on potential biomarkers in earthworms and appraised them in relation to basic requirements needed for supplying information relevant to devising satisfactory risk assessment. A wide range of potential biomarkers have been measured in earthworms, including DNA alteration, induction of metal-binding proteins (MTs and MBP), depression of ChE activity and other enzymatic responses, energy reserve responses, responses in neural impulse conductivity, lysosomal membrane stability, immunological responses, changes in sperm numbers, histopathological changes, and behavioral changes. Both organic and inorganic compounds have been included; however, for each biomarker the main emphasis historically has been placed on only a few chemicals. Dose-response relationships were in some cases observed. Little information is available on the linkage of the biomarker response to effects at population or community levels. The influence of other factors, biotic and abiotic, on the biomarker responses and their temporal duration have been only sporadically reported.
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Toxicity and chemical analyses of airport runoff waters in Poland.
Sulej, Anna Maria; Polkowska, Zaneta; Wolska, Lidia; Cieszynska, Monika; Namieśnik, Jacek
2014-05-01
The aim of this study was to assess the ecotoxicological effects of various compounds in complex airport effluents using a chemical and ecotoxicological integrated strategy. The present work deals with the determination of sum of PCBs, PAHs, pesticides, cations, anions, phenols, anionic, cationic, non-ionic detergents, formaldehyde and metals--as well as TOC and conductivity--in runoff water samples collected from 2009 to 2011 at several locations on two Polish international airports. Two microbiotests (Vibrio fischeri bacteria and the crustacean Thamnocephalus platyurus) have been used to determine the ecotoxicity of airport runoff waters. The levels of many compounds exceeded several or even several tens of times the maximum permissible levels. Analysis of the obtained data shows that samples that displayed maximum toxicity towards the bioindicators Vibrio fischeri were not toxic towards Thamnocephalus platyurus. Levels of toxicity towards T. platyurus are strongly correlated with pollutants that originate from the technological operations related to the maintenance of airport infrastructure. The integrated (chemical-ecotoxicological) approach to environmental contamination assessment in and around airports yields extensive information on the quality of the environment. These methodologies can be then used as tools for tracking the environmental fate of these compounds and for assessing the environmental effect of airports. Subsequently, these data will provide a basis for airport infrastructure management.
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Omics Advances in Ecotoxicology.
Zhang, Xiaowei; Xia, Pu; Wang, Pingping; Yang, Jianghu; Baird, Donald J
2018-04-03
Toxic substances in the environment generate adverse effects at all levels of biological organization from the molecular level to community and ecosystem. Given this complexity, it is not surprising that ecotoxicologists have struggled to address the full consequences of toxic substance release at ecosystem level, due to the limits of observational and experimental tools to reveal the changes in deep structure at different levels of organization. -Omics technologies, consisting of genomics and ecogenomics, have the power to reveal, in unprecedented detail, the cellular processes of an individual or biodiversity of a community in response to environmental change with high sample/observation throughput. This represents a historic opportunity to transform the way we study toxic substances in ecosystems, through direct linkage of ecological effects with the systems biology of organisms. Three recent examples of -omics advance in the assessment of toxic substances are explored here: (1) the use of functional genomics in the discovery of novel molecular mechanisms of toxicity of chemicals in the environment; (2) the development of laboratory pipelines of dose-dependent, reduced transcriptomics to support high-throughput chemical testing at the biological pathway level; and (3) the use of eDNA metabarcoding approaches for assessing chemical effects on biological communities in mesocosm experiments and through direct observation in field monitoring. -Omics advances in ecotoxicological studies not only generate new knowledge regarding mechanisms of toxicity and environmental effect, improving the relevance and immediacy of laboratory toxicological assessment, but can provide a wholly new paradigm for ecotoxicology by linking ecological models to mechanism-based, systems biology approaches.
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Keiter, Steffen; Rastall, Andrew; Kosmehl, Thomas; Wurm, Karl; Erdinger, Lothar; Braunbeck, Thomas; Hollert, Henner
2006-09-01
Fish populations, especially those of the grayling (Thymallus thymallus), have declined over the last two decades in the upper Danube River between Sigmaringen and Ulm, despite intensive and continuous stocking and improvement of water quality since the 1970s. Similar problems have been reported for other rivers, e.g. in Switzerland, Great Britain, the United States and Canada. In order to assess if ecotoxicological effects might be related to the decline in fish catch at the upper Danube River, sediment, suspended matter and waste water samples from sewage treatment plants were collected at selected locations and analyzed in a bioanalytical approach using a battery of bioassays. The results of this pilot study will be used to decide if a comprehensive weight-of-evidence study is needed. Freeze-dried sediments and suspended particulate matters were extracted with acetone in a Soxhlet apparatus. Organic pollutants from sewage water were concentrated using XAD-resins. In order to investigate the ecotoxicological burden, the following bioassays were used: (1) neutral red assay with RTL-W1 cells (cytotoxicity), (2) comet assay with RTL-W1 cells (genotoxicity), (3) Arthrobacter globiformis dehydrogenase assay (toxicity to bacteria), (4) yeast estrogen screen assay (endocrine disruption), (5) fish egg assay with the zebrafish (Danio rerio; embryo toxicity) and (6) Ames test with TA98 (mutagenicity). The results of the in vitro tests elucidated a considerable genotoxic, cytotoxic, mutagenic, bacteriotoxic, embryotoxic and estrogenic burden in the upper Danube River, although with a very inhomogeneous distribution of effects. The samples taken from Riedlingen, for example, induced low embryo toxicity, but the second highest 17beta-estradiol equivalent concentration (1.8 ng/L). Using the fish egg assay with native sediments, a broad range of embryotoxic effects could be elucidated, with clear-cut dose-response relationships for the embryotoxic effects of contaminated sediments. With native sediments, embryotoxicity was clearly higher than with corresponding pore waters, thus corroborating the view that--at least for fish eggs--the bioavailability of particle-bound lipophilic substances in native sediments is higher than generally assumed. The effect observed most frequently in the fish egg assay was a developmental delay. A comparison of our own results with locations along the rivers Rhine and Neckar demonstrated similar or even higher ranges of ecotoxicological burdens in the Danube River. The complex pattern of ecotoxicological effects caused by environmental samples from the Danube River, when assessed in an in vitro biotest battery using both acute and more specific endpoints, showed that integration of different endpoints is essential for appropriate hazard assessment. Overall, the ecotoxicological hazard potential shown has indeed to be considered as one potential reason for the decline in fish catches at the upper Danube River. However, based on the results of this pilot study, it is not possible to elucidate that chemically induced alterations are responsible for the fish decline. In order to confirm the ecological relevance of the in vitro results for the situation in the field and especially for the decline of the grayling and other fishes, further integrated investigations are required. For linking the weight of evidence obtained by in vitro assays and fish population investigations, the application of additional, more specific biomarkers (e.g. vitellogenin induction, EROD and micronucleus assay) has been initiated in fish taken from the field as well as in situ investigations.
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NASA Astrophysics Data System (ADS)
Traore, Harouna; Crouzet, Olivier; Mamy, Laure; Sireyjol, Christine; Rossard, Virginie; Servien, Remy; Latrille, Eric; Benoit, Pierre
2017-04-01
The understanding of the fate of pesticides and their environmental impacts largely relies on their molecular properties. We recently developed 'TyPol' (Typology of Pollutants), a clustering method based on statistical analyses combining several environmental endpoints (i.e. environmental parameters such as sorption coefficient, degradation half-life) and one ecotoxicological one (bioconcentration factor), and structural molecular descriptors (number of atoms in the molecule, molecular surface, dipole moment, energy of orbitals…). TyPol has been conceived on the available knowledge on QSAR of a wide diversity of organic compounds (Mamy et al., 2015). This approach also allows to focus on transformation products present in different clusters and to infer possible changes in environmental fate consecutively to different degradation processes (Servien et al., 2014; Benoit et al., 2016). The initial version of TyPol did not include any ecotoxicological parameters except the bioconcentration factor (BCF), which informs more on the transfer along the trophic chain rather than on the effects on non-target organisms. The objective was to implement the TyPol database with a data set of ecotoxicological data concerning pesticides and several aquatic and terrestrial organisms, in order to test the possibility to extend TyPol to ecotoxicological effects on various organisms. The data analysis (available literature and databases) revealed that relevant ecotoxicological endpoints for terrestrial organisms such as soil microorganisms and macroinvertebrates are lacking compared to aquatic organisms. We have added seven parameters for acute (EC50, LC50) and chronic (NOEC) toxicological effects for the following organisms: Daphnia, Algae, Lemna and Earthworm. In this new configuration, TyPol was used to classify about 45 pesticides in different behavioural and ecotoxicity clusters. The clustering results were analyzed to reveals relationships between molecular descriptors, environmental parameters and the added toxicological parameters. Some trends between soil adsorption or Kow coefficient and the acute toxicity towards earthworms or algae were highlighted, and discussed on the basis of the concept of contaminant bioavailability. This proof-of-concept study also showed that the in silico clustering method TyPol can successfully address new questions and can be expanded with other parameters of interest. Keywords: pesticides, toxicity, QSAR, clustering, PLS References : Servien R., Mamy L., Li Z., Rossard V., Latrille E., Bessac F., Patureau D., Benoit P., 2014. TyPol - A new methodology for organic compounds clustering based on their molecular characteristics and environmental behavior. Chemosphere, 111, 613-622. Mamy L., Patureau D., Barriuso E., Bedos C., Bessac F., Louchart X., Martin-Laurent F., Miege C., Benoit P., 2015. Prediction of the fate of organic compounds in the environment from their molecular properties: A review. Critical Reviews in Environmental Science and Technology, 45, 12, 1277-1377 (Open access). Benoit P., Mamy L., Servien R., Li Z., Latrille E., Rossard V., Bessac F., Patureau D., Martin-Laurent F. 2017. Categorizing chlordecone potential degradation products to explore their environmental fate. Science of the Total Environment, 574, 781-795.
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METABOLOMICS IN SMALL FISH TOXICOLOGY AND OTHER ENVIRONMENTAL APPLICATIONS
Although lagging behind applications targeted to human endpoints, metabolomics offers great potential in environmental applications, including ecotoxicology. Indeed, the advantages of metabolomics (relative to other 'omic techniques) may be more tangible in ecotoxicology because...
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Terrestrial ecotoxicology is the study of how environmental pollutants affect land-dependent organisms and their environment. It requires three elements: (1) a source, (2) a receptor, and (3) an exposure pathway. This article reviews the basic principles of each of each element...
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Hendriks, A J
1995-11-01
A model was designed and calibrated with accumulation data to calculate the internal concentrations of microcontaminants in organisms as a function of a few constants and variables. The main factors are the exposure time, the external exposure concentration, the partition ratio of the compound, and the size of the taxon concerned. The model was applied to calculate the lethal and sublethal body burdens of several priority compounds and some major taxa. Estimations were generally confirmed at the order of magnitude level by measured residues and applied doses if available. According to the estimations, most priority compounds chosen were critical for most taxa above internal concentrations of 0.1 mmol.kg-1 wet wt. Trichloromethane, 1,2,4-trichlorobenzene, and hexachlorobenzene were lethal above this level only, whereas other organic microcontaminants affected at least some taxa at lower body burdens. The log(Kow) of the organic compounds ranged from 2.0 to 7.0. Keeping in mind that bioconcentration and -magnification ratios for metals may be quite variable, the lowest critical residues estimated were just below the value of 0.1 mmol.kg-1 wet wt. Here, external concentrations encountered in natural habitats seem to be a promising tool for predictive comparative ecotoxicology. The critical body burdens for plants and invertebrates may have been overestimated due to uncertainty about the parameters. Among the different taxa, however, the fish families chosen (Salmonidae and Cyprinidae) seem to be most sensitive to most compounds. Internal response concentrations of the herbicide atrazine were the lowest in micro- and macrophytes, whereas parathion affected invertebrates at low levels. The database that provided the external response concentrations was also consulted to estimate so-called extrapolation or safety factors. On average, long-term no effect concentrations in water are estimated to be about 10-30 times below short-term median lethal levels. In general, short-term versus long-term, lethal versus sublethal, and median versus no response concentration ratios each contributed factors of about 2-3 to this overall ratio. The model for internal concentrations indicated that the ratio between the short-term and the long-term LC50 will be high for large species and high octanol-water partition ratios.
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Toxicological and ecotoxicological assessment of water tracers
NASA Astrophysics Data System (ADS)
Behrens, H.; Beims, U.; Dieter, H.; Dietze, G.; Eikmann, T.; Grummt, T.; Hanisch, H.; Henseling, H.; Käß, W.; Kerndorff, H.; Leibundgut, C.; Müller-Wegener, U.; Rönnefahrt, I.; Scharenberg, B.; Schleyer, R.; Schloz, W.; Tilkes, F.
2001-06-01
Uncertainties regarding possible negative effects on the environment or on human health of authorizing tracing experiments in groundwater and surface waters led to the establishment of a Working Group at the German Federal Environmental Agency (Umweltbundesamt - UBA) for conducting a toxicological and ecotoxicological assessment. A total of 17 water tracers was assessed by the Working Group on the basis of the results of toxicological tests, the available literature, and the group's expert knowledge. In the future, tracers that pose a risk to the environment or to human health should no longer be used. Nevertheless, there are a number of tracers that could be used in hydrogeological and hydrological investigations for water-pollution-control purposes with no adverse environmental impact.
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Metabolomics in Small Fish Toxicology: Assessing the Impacts of Model EDCs
Although lagging behind applications targeted to human endpoints, metabolomics offers great potential in environmental applications, including ecotoxicology. Indeed, the advantages of metabolomics (relative to other ‘omic techniques) may be more tangible in ecotoxicology because...
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A Computational Model for Oocyte Growth Dynamics in Fathead Minnows
Molecular biomarkers have been used in ecotoxicological studies to evaluate the effects of endocrine disrupting chemicals in fish. Changes in these molecular biomarkers must then be linked to the effects upon reproduction in individuals, and subsequently populations. To meet th...
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A Computational Model for Oocyte Growth Dynamics in Fathead Minnows (Pimephales promelas)
Molecular biomarkers have been used in ecotoxicological studies to evaluate the effects of endocrine disrupting chemicals in fish. Ideally, changes in these molecular biomarkers should be linked to the effects upon reproduction in individuals, and subsequently populations. To m...
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Applications of AOPs to ecotoxicology
Toxicologists conducting safety assessments for either human or ecological health are responsible for generating data for possible adverse effects of a rapidly increasing number of substances. For example, the Registration, Evaluation, Authorisation and Restriction of Chemicals (...
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Handbook of Ecotoxicology. Second Edition.. Lewis Publishers, Boca Raton, FL. 32 p.
Phytoplankton, benthic and epiphytic microalgae, and macroalgae are energy sources critical to most aquatic ecosystems. Changes in their density and composition can effect the chemical and...
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Mater, N; Geret, F; Castillo, L; Faucet-Marquis, V; Albasi, C; Pfohl-Leszkowicz, A
2014-02-01
Ciprofloxacin (CIP), tamoxifen (TAM) and cyclophosphamide (CP) which are often used in anticancer treatment are released in hospital effluent and into the environment. Although the concentrations are low (from ng/L to μg/L), no data exist concerning their ecotoxicological impact. In this study two biomarkers of early effect were performed on hepatic cells (HepG2): cell viability and genotoxicity (DNA breaks) using cell proliferative assay and comet assay, respectively. These data were compared with two standardized ecotoxicological tests: algaltoxkit F™ and microtox®. Cells were exposed to an increasing amount of an individual drug or in a mixture for 24, 48 or 72h. The time-exposure of bacteria and algae ranged between 5 and 30min and 72h, respectively. A non-monotonic dose-response on cell viability was observed when HepG2 cells were exposed to TAM alone or in the presence of CIP. The same scheme was observed with microtox® when the bacteria were exposed to the mixtures. On the other side, an individual drug does not induce any DNA breaks on hepatic cells, whereas a mixture leads to a dose dependent increase of DNA breaks. Similarly a positive response was observed with algaltoxkit F™ only with mixtures. Synergistic effects observed when drugs are in a mixture highlight the importance of investigating the ecotoxicological effects of contaminants at low concentrations and in mixtures. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Net, Sopheak; Sempéré, Richard; Delmont, Anne; Paluselli, Andrea; Ouddane, Baghdad
2015-04-07
Because of their large and widespread application, phthalates or phthalic acid esters (PAEs) are ubiquitous in all the environmental compartements. They have been widely detected throughout the worldwide environment. Indoor air where people spend 65-90% of their time is also highly contaminated by various PAEs released from plastics, consumer products as well as ambient suspended particulate matter. Because of their widespread application, PAEs are the most common chemicals that humans are in contact with daily. Based on various exposure mechanisms, including the ingestion of food, drinking water, dust/soil, air inhalation and dermal exposure the daily intake of PAEs may reach values as high as 70 μg/kg/day. PAEs are involved in endocrine disrupting effects, namely, upon reproductive physiology in different species of fish and mammals. They also present a variety of additional toxic effects for many other species including terrestrial and aquatic fauna and flora. Therefore, their presence in the environment has attracted considerable attention due to their potential impacts on ecosystem functioning and on public health. This paper is a synthesis of the extensive literature data on behavior, transport, fate and ecotoxicological state of PAEs in environmental matrices: air, water, sediment, sludge, wastewater, soil, and biota. First, the origins and physicochemical properties of PAEs that control the behavior, transport and fate in the environment are reviewed. Second, the compilation of data on transport and fate, adverse environmental and human health effects, legislation, restrictions, and ecotoxicological state of the environment based on PAEs is presented.
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Chen, Shangchao; Chen, Mindong; Wang, Zhuang; Qiu, Weijian; Wang, Junfeng; Shen, Yafei; Wang, Yajun; Ge, Shun
2016-07-01
This paper aims to acquire the experimental data on the eco-toxicological effects of agricultural pollutants on the aquatic plants and the data can support the assessment of toxicity on the phytoplankton. The pesticide of Chlorpyrifos used as a good model to investigate its eco-toxicological effect on the different microalgae in freshwater. In order to address the pollutants derived from forestry and agricultural applications, freshwater microalgae were considered as a good sample to investigate the impact of pesticides such as Chlorpyrifos on aquatic life species. Two microalgae of Chlorella pyrenoidosa and Merismopedia sp. were employed to evaluate toxicity of Chlorpyrifos in short time and long time by means of measuring the growth inhibition rate, the redox system and the content of chlorophyll a, respectively. In this study, the results showed that EC50 values ranging from 7.63 to 19.64mg/L, indicating the Chlorpyrifos had a relatively limited to the growth of algae during the period of the acute toxicity experiment. Moreover, when two kinds of algae were exposed to a medium level of Chlorpyrifos, SOD and CAT activities were importantly advanced. Therefore, the growth rate and SOD and CAT activities can be highly recommended for the eco-toxicological assessment. In addition, chlorophyll a also could be used as a targeted parameter for assessing the eco-toxicity of Chlorpyrifos on both Chlorella pyrenoidosa and Merismopedia sp. Copyright © 2016 Elsevier B.V. All rights reserved.
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ECOTOXICOLOGY AND RISK ASSESSMENT FOR WETLANDS
This volume represents the proceedings of a workshop held from 30 July-3 August 1995 at Fairmont Hot Springs, Montana. The workshop was designed to meet the scientific and regulatory need for current information describing ecotoxicology and risk assessment for wetlands. Professio...
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Adverse Outcome Pathways in Ecotoxicology Research
Just as for chemical risk assessments for human health, ecotoxicology risk assessments face the daunting challenge posed by the large number of chemicals currently in use that could potentially impact the environment. In addition, the limited amount of toxicological data on many ...
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Ecotoxicological sediment evaluations in marine aquaculture areas of Chile.
Rudolph, Anny; Medina, Paulina; Urrutia, Carolina; Ahumada, Ramón
2009-08-01
Given its geographic characteristics, the southern Chilean fjord area is subjected to growing environmental pressure from the development of diverse forms of aquaculture (i.e., fish, algae, shellfish). The sediments accumulate substances as a natural sink, and ecotoxicology assays offer a reliable and robust proxy for sediment quality analyses. This study's objective was to establish a mid-range toxicity base line for the sediments in the region by applying a battery of non-specific ecotoxicological assays. Sediment samples (28) were collected in the channels and fjords studied during the CIMAR-Fiordos 11 cruise (July 2005). The sediments were evaluated using different species endemic to the eastern Pacific as targets: Ampelisca araucana, Tisbe longicornis, Arbacia spatuligera, and Dunaliella tertiolecta. The conditions for each assay were reported previously. Of the four species used as ecotoxicological tools, only D. tertiolecta differed significantly from the control group (negative) in terms of its growth. This difference could be attributed to nutrient enrichment. In general, we concluded that, although local changes occurred in the sediments, the mesoscale magnitude of the ecotoxicological alterations was small. Nonetheless, a surveillance program should be implemented that would allow us to follow-up and analyze the changes that are taking place in the systems on broader scales of time and space.
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Belhaj, Dalel; Athmouni, Khaled; Jerbi, Bouthaina; Kallel, Monem; Ayadi, Habib; Zhou, John L
2016-12-01
The occurrence, fate and ecotoxicological assessment of selected estrogenic compounds were investigated at Tunisian urban sewage treatment plant. The influents, effluents, as well as primary, secondary and dehydrated sludge, were sampled and analyzed for the target estrogens to evaluate their fate. All target compounds were detected in both sewage and sludge with mean concentrations from 0.062 to 0.993 μg L -1 and from 11.8 to 792.9 μg kg -1 dry weight, respectively. A wide range of removal efficiencies during the treatment processes were observed, from 6.3 % for estrone to 76.8 % for estriol. Ecotoxicological risk assessment revealed that the highest ecotoxicological risk in sewage effluent and dehydrated sludge was due to 17β-estradiol with a risk quotient (RQ) of 4.6 and 181.9, respectively, and 17α-ethinylestradiol with RQ of 9.8 and 14.85, respectively. Ecotoxicological risk after sewage discharge and sludge disposal was limited to the presence of 17β-estradiol in dehydrated-sludge amended soil with RQ of 1.38. Further control of estrogenic hormones in sewage effluent and sludge is essential before their discharge and application in order to prevent their introduction into the natural environment.
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Cohen, J.B.; Rattner, B.A.; Golden, N.H.
2003-01-01
The 'Contaminant Exposure and Effects--Terrestrial Vertebrates' (CEE-TV) database contains 4,336 records of ecotoxicological information for free-ranging amphibians, reptiles, birds, and mammals residing in Atlantic and Florida Gulf coast estuaries and their drainages. To identify spatial data gaps, those CEE-TV records for which the specific study location were known (n=2,740) were combined with watershed and wildlife management unit boundaries using Geographic Information Systems software. The U.S. Environmental Protection Agency's Index of Watershed Indicators (IWI), which classifies watersheds based on water quality and their vulnerability to pollution, was used to prioritize these data gaps. Of 136 watersheds in the study area, 15 that are classified by the IWI as having water quality problems or high vulnerability to pollution lacked terrestrial vertebrate ecotoxicological monitoring or research in the past decade. Older studies within some of these watersheds documented high levels of contaminants in wildlife tissues. Of 90 National Wildlife Refuge units, 42 without current data fall within watersheds of concern. Of 40 National Park units larger than 1 km2, 17 without current data fall within watersheds of concern. Issues encountered in this analysis highlighted the need for spatially and temporally replicated field monitoring programs that utilize random sampling. Without data from such studies, it will be difficult to perform unbiased assessments of regional trends in contaminant exposure and effects in terrestrial vertebrates.
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Cohen, Jonathan B; Rattner, Barnett A; Golden, Nancy H
2003-01-01
The "Contaminant Exposure and Effects-Terrestrial Vertebrates" (CEE-TV) database contains 4,336 records of ecotoxicological information for free-ranging amphibians, reptiles, birds, and mammals residing in Atlantic and Florida Gulf coast estuaries and their drainages. To identify spatial data gaps, those CEE-TV records for which the specific study location were known (n = 2,740) were combined with watershed and wildlife management unit boundaries using Geographic Information Systems software. The US Environmental Protection Agency's Index of Watershed Indicators (IWI), which classifies watersheds based on water quality and their vulnerability to pollution, was used to prioritize these data gaps. Of 136 watersheds in the study area, 15 that are classified by the IWI as having water quality problems or high vulnerability to pollution lacked terrestrial vertebrate ecotoxicological monitoring or research in the past decade. Older studies within some of these watersheds documented high levels of contaminants in wildlife tissues. Of 90 National Wildlife Refuge units, 42 without current data fall within watersheds of concern. Of 40 National Park units larger than 1 km2, 17 without current data fall within watersheds of concern. Issues encountered in this analysis highlighted the need for spatially and temporally replicated field monitoring programs that utilize random sampling. Without data from such studies, it will be difficult to perform unbiased assessments of regional trends in contaminant exposure and effects in terrestrial vertebrates.
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Ecotoxicological responses of three ornamental herb species to cadmium.
Liu, Zhouli; He, Xingyuan; Chen, Wei; Zhao, Mingzhu
2013-08-01
Cadmium is one of the most toxic elements. The ideal vegetal cover should be ensured by the selection of appropriate plant species for successful phytoremediation. In the present study, the ecotoxicological effects of Cd on the following 3 ornamental herbs were investigated: Italian ryegrass (Lolium multiflorum Lam.), white clover (Trifolium repens L.), and alfalfa (Medicago sativa L.). Based on the inhibition rate of seed germination, root and shoot elongation, early seedling growth, median inhibition concentration (IC50) values, and index of tolerance (IT) values, ecotoxicological indicators were determined. The results showed that 10 μM to 50 μM Cd had little effect on seed germination or root and shoot elongation of the 3 ornamental herbs (p > 0.01). With an increase in Cd concentrations, alfalfa (M. sativa) was the most sensitive to Cd toxicity in terms of seed germination and root elongation. Based on the IC50 of root elongation, Italian ryegrass (L. multiflorum) was the least sensitive to Cd. Based on the IC50 of seed germination and shoot elongation, white clover had the least sensitivity to Cd. Among the 3 ornamental herbs, based on the IC50 of seed germination and root and shoot elongation, alfalfa (M. sativa) was all the most sensitive plant. According to the index of tolerance, Italian ryegrass (L. multiflorum) was the most tolerant plant. Copyright © 2013 SETAC.
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Justino, Celine I L; Pereira, Ruth; Freitas, Ana C; Rocha-Santos, Teresa A P; Panteleitchouk, Teresa S L; Duarte, Armando C
2012-03-01
The olive oil mill wastewater (OMW) is a problematic and polluting effluent which may degrade the soil and water quality, with critical negative impacts on ecosystems functions and services provided. The main purpose of this review paper is presenting the state of the art of OMW treatments focusing on their efficiency to reduce OMW toxicity, and emphasizing the role of ecotoxicological tests on the evaluation of such efficiency before the up-scale of treatment methodologies being considered. In the majority of research works, the reduction of OMW toxicity is related to the degradation of phenolic compounds (considered as the main responsible for the toxic effects of OMW on seed germination, on bacteria, and on different species of soil and aquatic invertebrates) or the decrease of chemical oxygen demand content, which is not scientifically sound. Batteries of ecotoxicological tests are not applied before and after OMW treatments as they should be, thus leading to knowledge gaps in terms of accurate and real assessment of OMW toxicity. Although the toxicity of OMW is usually high, the evaluation of effects on sub-lethal endpoints, on individual and multispecies test systems, are currently lacking, and the real impacts yielded by its dilution, in freshwater trophic chains of receiving systems can not be assessed. As far as the terrestrial compartment is considered, ecotoxicological data available include tests only with plants and the evaluation of soil microbial parameters, reflecting concerns with the impacts on crops when using OMW for irrigation purposes. The evaluation of its ecotoxicity to other edaphic species were not performed giving rise to a completely lack of knowledge about the consequences of such practice on other soil functions. OMW production is a great environmental problem in Mediterranean countries; hence, engineers, chemists and ecotoxicologists should face this problem together to find an ecologically friend solution.
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Osorio, Victoria; Larrañaga, Aitor; Aceña, Jaume; Pérez, Sandra; Barceló, Damià
2016-01-01
Considerable amounts of pharmaceuticals are used in human and veterinary medicine, which are not efficiently removed during wastewater and slurries treatment and subsequently entering continuously into freshwater systems. The intrinsic biological activity of these non-regulated pollutants turns their presence in the aquatic environment into an ecological matter of concern. We present the first quantitative study relating the presence of pharmaceuticals and their predicted ecotoxicological effects with human population and livestock units. Four representative Iberian River basins (Spain) were studied: Llobregat, Ebro, Júcar and Guadalquivir. The levels of pharmaceuticals were determined in surface water and sediment samples collected from 77 locations along their stream networks. Predicted total toxic units to algae, Daphnia and fish were estimated for pharmaceuticals detected in surface waters. The use of chemometrics enabled the study of pharmaceuticals for: their spatial distribution along the rivers in two consecutive years; their potential ecotoxicological risk to aquatic organisms; and the relationships among their occurrence and predicted ecotoxicity with human population and animal farming pressure. The Llobregat and the Ebro River basins were characterized as the most polluted and at highest ecotoxicological risk, followed by Júcar and Guadalquivir. No significant acute risks of pharmaceuticals to aquatic organisms were observed. However potential chronic ecotoxicological effects on algae could be expected at two hot spots of pharmaceuticals pollution identified in the Llobregat and Ebro basins. Analgesics/antiinflammatories, antibiotics and diuretics were the most relevant therapeutic groups across the four river basins. Among them, hydrochlorothiazide and gemfibrozil, as well as azithromycin and ibuprofen were widely spread and concentrated pharmaceuticals in surface waters and sediments, respectively. Regarding their predicted ecotoxicity, sertraline, gemfibrozil and loratidine were identified as the more concerning compounds. Significantly positive relationships were found among levels of pharmaceuticals and toxic units and population density and livestock units in both surface water and sediment matrices. Copyright © 2015. Published by Elsevier B.V.
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78 FR 1856 - Availability of Draft Chemical Risk Assessments; Public Comment Opportunity
Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-09
... bioaccumulation, environmental risk assessment (aquatic and terrestrial), and analytical chemistry of organic... organics, experts on use of volatiles as solvent degreasers and in the arts/crafts field, chemical...: Exposure modeling, aquatic ecotoxicology, terrestrial ecotoxicology, inorganic chemistry addressing water...
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ECOTOX (ECOTOXICOLOGY DATABASE): AN ASSESSMENT TOOL FOR THE 21ST CENTURY
The ECOTOX (ECOTOXicology Database) system developed by the U.S. EPA, National Health and Environmental Effecrs Research Laboratory (NHEERL), Mid-Continent Ecology Division in Duluth, MN, (MED-Duluth), provides a web browser search interface for locating aquatic and terrestrial t...
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Matthiessen, Peter; Ankley, Gerald T.; Biever, Ronald C.; Bjerregaard, Poul; Borgert, Christopher; Brugger, Kristin; Blankinship, Amy; Chambers, Janice; Coady, Katherine K.; Constantine, Lisa; Dang, Zhichao; Denslow, Nancy D.; Dreier, David; Dungey, Steve; Gray, L. Earl; Gross, Melanie; Guiney, Patrick D.; Hecker, Markus; Holbech, Henrik; Iguchi, Taisen; Kadlec, Sarah; Karouna-Renier, Natalie K.; Katsiadaki, Ioanna; Kawashima, Yukio; Kloas, Werner; Krueger, Henry; Kumar, Anu; Lagadic, Laurent; Leopold, Annegaaike; Levine, Steven L.; Maack, Gerd; Marty, Sue; Meador, James P.; Mihaich, Ellen; Odum, Jenny; Ortego, Lisa; Parrott, Joanne L.; Pickford, Daniel; Roberts, Mike; Schaefers, Christoph; Schwarz, Tamar; Solomon, Keith; Verslycke, Tim; Weltje, Lennart; Wheeler, James R.; Williams, Mike; Wolf, Jeffery C.; Yamazaki, Kunihiko
2017-01-01
A SETAC Pellston Workshop® “Environmental Hazard and Risk Assessment Approaches for Endocrine-Active Substances (EHRA)” was held in February 2016 in Pensacola, Florida, USA. The primary objective of the workshop was to provide advice, based on current scientific understanding, to regulators and policy makers; the aim being to make considered, informed decisions on whether to select an ecotoxicological hazard- or a risk-based approach for regulating a given endocrine-disrupting substance (EDS) under review. The workshop additionally considered recent developments in the identification of EDS. Case studies were undertaken on 6 endocrine-active substances (EAS—not necessarily proven EDS, but substances known to interact directly with the endocrine system) that are representative of a range of perturbations of the endocrine system and considered to be data rich in relevant information at multiple biological levels of organization for 1 or more ecologically relevant taxa. The substances selected were 17α-ethinylestradiol, perchlorate, propiconazole, 17β-trenbolone, tributyltin, and vinclozolin. The 6 case studies were not comprehensive safety evaluations but provided foundations for clarifying key issues and procedures that should be considered when assessing the ecotoxicological hazards and risks of EAS and EDS. The workshop also highlighted areas of scientific uncertainty, and made specific recommendations for research and methods-development to resolve some of the identified issues. The present paper provides broad guidance for scientists in regulatory authorities, industry, and academia on issues likely to arise during the ecotoxicological hazard and risk assessment of EAS and EDS. The primary conclusion of this paper, and of the SETAC Pellston Workshop on which it is based, is that if data on environmental exposure, effects on sensitive species and life-stages, delayed effects, and effects at low concentrations are robust, initiating environmental risk assessment of EDS is scientifically sound and sufficiently reliable and protective of the environment. In the absence of such data, assessment on the basis of hazard is scientifically justified until such time as relevant new information is available.
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Mode of Action (MOA) Assignment Classifications for Ecotoxicology: An Evaluation of approaches
The mode of toxic action (MOA) is recognized as a key determinant of chemical toxicity and as an alternative to chemical class-based predictive toxicity modeling. However, MOA classification has never been standardized in ecotoxicology, and a comprehensive comparison of classific...
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A Vision and Strategy:Predictive Ecotoxicology in the 21st Century
The manuscript provides an introduction and overview for a series of five papers resulting from a SETAC Pellston Workshop titled A Vision and Strategy for Predictive Ecotoxicology in the 21st Century: Defining Adverse Outcome Pathways Associated with Ecological Risk. It proposes...
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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
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Aquatic ecotoxicology: from the ecosystem to the cellular and molecular levels.
Boudou, A; Ribeyre, F
1997-01-01
This review of aquatic ecotoxicology is presented in three parts. First, we discuss the fundamental concepts and stress the importance of its ecological basis and the complexity and diversity of the field of investigation, which result from actions and interactions between the physicochemical characteristics of the biotopes, the structural and functional properties of the living organisms, and the contamination modalities. Ecotoxicological mechanisms, regardless of the level of biological complexity, primarily depend on the bioavailability of the toxic products. Numerous processes control the chemical fate of contaminants in the water column and/or sediment compartments; accessibility to the biological barriers that separate the organisms from their surrounding medium depends directly on bioavailability. Second, we review the principal methodologies of the field, from in situ studies at the ecosystem/ecocomplex level to bioassays or single species tests. Third, we focus on mercury, selected as a reference contaminant, in order to illustrate the main ecotoxicological concepts, the complementarity between field and laboratory studies, and the indispensable multidisciplinarity of the approaches. PMID:9114275
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Martin, Francis L; Semple, Kirk T
2004-09-01
Speakers: John Ashby (Syngenta CTL, UK), Peter A. Behnisch (Eurofins GfA, Germany), Paul L. Carmichael (Unilever Colworth, UK), Curtis C.Harris (National Cancer Institute, USA), Kevin C. Jones (Lancaster University, UK), Andreas Kortenkamp (School of Pharmacy, London, UK), Caroline J. Langdon (Reading University, UK), Anthony M. Lynch (GlaxoSmithKline, UK), Francis L. Martin (Lancaster University, UK), Trevor J. McMillan (Lancaster University, UK), David H. Phillips (Institute of Cancer Research, UK), Huw J. Ricketts (University of Cardiff, UK), Michael N. Routledge (University of Leeds, UK), J. Thomas Sanderson (Utrecht University, The Netherlands) and Kirk T. Semple (Lancaster University, UK) The effects of many environmental exposures to either single contaminants or to mixtures still remain to be properly assessed in ecotoxicological and human toxicological settings. Such assessments need to be carried out using relevant biological assays. On a mechanistic basis, future studies need to be able to extrapolate exposure to disease risk. It is envisaged that such an approach would lead to the development of appropriate strategies to either reduce exposures or to initiate preventative measures in susceptible individuals or populations. To mark the opening of a new Institute, the Lancaster Environmental Centre, an environmental health workshop was held over 2 days (9-10 September 2003) at Lancaster University, UK. The fate, behaviour and movement of chemicals in the environment, together with environmental exposures and human health, biomarkers of such exposures, hormone-like compounds and appropriate genetic toxicology methodologies, were discussed.
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Barmentlo, S Henrik; Schrama, Maarten; Hunting, Ellard R; Heutink, Roel; van Bodegom, Peter M; de Snoo, Geert R; Vijver, Martina G
2018-08-01
Agricultural ditches host a diverse community of species. These species often are unwarrantedly exposed to fertilizers and a wide-array of pesticides (hereafter: agrochemicals). Standardized ecotoxicological research provides valuable information to predict whether these pesticides possibly pose a threat to the organisms living within these ditches, in particular macro-invertebrates. However, knowledge on how mixtures of these agrochemicals affect macro-invertebrates under realistic abiotic conditions and with population and community complexity is mostly lacking. Therefore we examined here, using a full factorial design, the population responses of macroinvertebrate species assemblages exposed to environmentally relevant concentrations of three commonly used agrochemicals (for 35days) in an outdoor experiment. The agrochemicals selected were an insecticide (imidacloprid), herbicide (terbuthylazine) and nutrients (NPK), all having a widespread usage and often detected together in watersheds. Effects on species abundance and body length caused by binary mixture combinations could be described from single substance exposure. However, when agrochemicals were applied as tertiary mixtures, as they are commonly found in agricultural waters, species' abundance often deviated from expectations made based on the three single treatments. This indicates that pesticide-mixture induced toxicity to population relevant endpoints are difficult to extrapolate to field conditions. As in agricultural ditches often a multitude (approx. up to 7) of agrochemicals residues are detected, we call other scientist to verify the ecological complexity of non-additive induced shifts in natural aquatic invertebrate populations and aquatic species assemblages. Copyright © 2018 Elsevier B.V. All rights reserved.
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Ecotoxicological models generally have large data requirements and are frequently based on existing information from diverse sources. Standardizing data for toxicological models may be necessary to reduce extraneous variation and to ensure models reflect intrinsic relationships. ...
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Comparative studies on ecotoxicology of synthetic detergents.
Lal, H; Misra, V; Viswanathan, P N; Krishna Murti, C R
1983-12-01
To predict the comparative toxicological response of synthetic detergents on aquatic ecosystems, the effects of various concentrations of neutralized alkyl benzene sulfonate were studied. The median tolerance limit at 48 hr, 95% confidence limit, slope function, presumable harmless concentration, and rate of survival of different species of aquatic fauna such as water fleas (Daphnia magna), mosquito larvae (Culex pipiens), slug worms (Tubifex rivulorum), snails (Lymnaea vulgaris), tadpoles (Rana cyanophlyctis), and fish fingerlings (Cirrhina mrigala) were followed at 0, 24, 48, 72, and 96 hr. Any effect on quality of the water was also tested after the addition of various concentrations of detergents. The results showed that water fleas are more susceptible to detergent toxicity than fish fingerlings, tadpoles, slug worms, snails, and mosquito larvae. Behavioral changes were also observed as an index for detergent toxicity. The relative toxicity of the detergents to various species is discussed in relation to selective ecotoxicological response.
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Gredelj, Andrea; Barausse, Alberto; Grechi, Laura; Palmeri, Luca
2018-06-20
Over the past decades, per- and polyfluoroalkyl substances (PFASs) found in environmental matrices worldwide have raised concerns due to their toxicity, ubiquity and persistence. A widespread pollution of groundwater and surface waters caused by PFASs in Northern Italy has been recently discovered, becoming a major environmental issue, also because the exact risk for humans and nature posed by this contamination is unclear. Here, the Po River in Northern Italy was selected as a study area to assess the ecological risk posed by perfluoroalkyl acids (PFAAs), a class of PFASs, considering the noticeable concentration of various PFAAs detected in the Po waters over the past years. Moreover, the Po has a large environmental and socio-economic importance: it is the largest Italian river and drains a densely inhabited, intensely cultivated and heavily industrialized watershed. Predicted no-effect concentrations (PNECs) were derived using two regulated methodologies, assessment factors (AFs) and species sensitivity distribution (SSD), which rely on published ecotoxicological laboratory tests. Results were compared to those of a novel methodology using the mechanistic ecosystem model AQUATOX to compute PNECs in an ecologically-sound manner, i.e. considering physical, chemical, biological and ecological processes in the river. The model was used to quantify how the biomasses of the modelled taxa in the river food web deviated from natural conditions due to varying inputs of the chemicals. PNEC for each chemical was defined as the lowest chemical concentration causing a non-negligible yearly biomass loss for a simulated taxon with respect to a control simulation. The investigated PFAAs were Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) as long-chained compounds, and Perfluorobutanoic acid (PFBA) and Perfluorobutanesulfonic acid (PFBS) as short-chained homologues. Two emerging contaminants, Linear Alkylbenzene Sulfonate (LAS) and triclosan, were also studied to assess the performance of the three methodologies for chemicals whose ecotoxicology and environmental fate are well-studied. The most precautionary approach was the use of AFs generally followed by SSD and then AQUATOX, except for PFOS, for which AQUATOX yielded a much lower PNEC compared to the other approaches since, unlike the other two methodologies, it explicitly simulates sublethal toxicity and indirect ecological effects. Our findings highlight that neglecting the role of ecological processes when extrapolating from laboratory tests to ecosystems can result in under-protective threshold concentrations for chemicals. Ecosystem models can complement existing laboratory-based methodologies, and the use of multiple methods for deriving PNECs can help to clarify uncertainty in ecological risk estimates. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Lombardo, Andrea; Franco, Antonio; Pivato, Alberto; Barausse, Alberto
2015-03-01
Conventional approaches to estimating protective ecotoxicological thresholds of chemicals, i.e. predicted no-effect concentrations (PNEC), for an entire ecosystem are based on the use of assessment factors to extrapolate from single-species toxicity data derived in the laboratory to community-level effects on ecosystems. Aquatic food web models may be a useful tool to improve the ecological realism of chemical risk assessment because they enable a more insightful evaluation of the fate and effects of chemicals in dynamic trophic networks. A case study was developed in AQUATOX to simulate the effects of the anionic surfactant linear alkylbenzene sulfonate and the antimicrobial triclosan on a lowland riverine ecosystem. The model was built for a section of the River Thames (UK), for which detailed ecological surveys were available, allowing for a quantification of energy flows through the whole ecosystem. A control scenario was successfully calibrated for a simulation period of one year, and tested for stability over six years. Then, the model ecosystem was perturbed with varying inputs of the two chemicals. Simulations showed that both chemicals rapidly approach steady-state, with internal concentrations in line with the input bioconcentration factors throughout the year. At realistic environmental concentrations, both chemicals have insignificant effects on biomass trends. At hypothetical higher concentrations, direct and indirect effects of chemicals on the ecosystem dynamics emerged from the simulations. Indirect effects due to competition for food sources and predation can lead to responses in biomass density of the same magnitude as those caused by direct toxicity. Indirect effects can both exacerbate or compensate for direct toxicity. Uncertainties in key model assumptions are high as the validation of perturbed simulations remains extremely challenging. Nevertheless, the study is a step towards the development of realistic ecological scenarios and their potential use in prospective risk assessment of down-the-drain chemicals. Copyright © 2014 Elsevier B.V. All rights reserved.
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A main goal of ecotoxicology and risk assessment is to assess the impact on aquatic populations. However the most widely used bioassays measure the response of individuals to infer population effects. Bridging the gap between established individual-based methodology and the popul...
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1986-12-01
Exposures of Tradescantia and Ambrosia dumosa Tradescantia plants were cultivated specifically for this study in a greenhouse in Columbia, MO...relevant to ecotoxicology . In SupplementaryPapers - to Testing for the Effects of Chemicals on Ecosystems. pp. 119-132. National Academy of Sciences
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Linking genotoxic responses and reproductive success in ecotoxicology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Anderson, S.L.; Wild, G.C.
1994-12-01
The potential of genotoxicity biomarkers as predictors of detrimental environmental effects, such as altered reproductive success of wild organisms, must be rigorously determined. Recent research to evaluate relationships between genotoxic responses and indicators of reproductive success in model animals is described from an ecotoxicological perspective. Genotoxicity can be correlated with reproductive effects such as gamete loss due to cell death; embryonic mortality; and heritable mutations in a range of model animals including polychaete worms, nematodes, sea urchins, amphibians, and fish. In preliminary studies, the polychaete worm, Neanthes arenaceodentata, and the nematode, Caenorhabditis elegans, have also shown the potential for cumulativemore » DNA damage in gametes. If DNA repair capacity is limited in gametes, then selected life history traits such as long and synchronous periods of gametogenesis may confer vulnerability to genotoxic substances in chronic exposures. Recommendations for future research include strategic development of animal models that can be used to elucidate multiple mechanisms of effect (multiend point) at varying levels of biological organization (multilevel). 27 refs., 2 tabs.« less
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Engineered nanomaterials (ENMs) are increasingly entering the environment with uncertain consequences including potential ecological effects. Various research communities view differently whether ecotoxicological testing of ENMs should be conducted using environmentally relevant ...
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EPA MED-DULUTH'S ECOTOX AND ECO-SSL WEB APPLICATIONS
The ECOTOX (ECOTOXicology Database) system developed by the USEPA, National Health and Environmental Effects Research Laboratory (NHEERL), Mid-Continent Ecology Division in Duluth, MN (MED-Duluth), provides a web browser search interface for locating aquatic and terrestrial toxic...
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Cross-species extrapolation of chemical effects: Challenges and new insights
One of the greatest uncertainties in chemical risk assessment is extrapolation of effects from tested to untested species. While this undoubtedly is a challenge in the human health arena, species extrapolation is a particularly daunting task in ecological assessments, where it is...
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1989-10-01
1978. " Ecotoxicology of aquatic plant communi- ties," Principles of Ecotoxicology , SCOPE Report 12, Chapter 11, pp 239-255. [Heavy metals, Pollutants...Phragmites communis and Equisetum limosum were cultivated . They found plant-plant influences depend on soil type. Typha latifolia, S. A2 lacustris, and
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METABOLOMICS IN SMALL FISH TOXICOLOGY AND ECOLOGICAL RISK ASSESSMENTS
The US EPA is tasked with protecting not only humans, but also ecosystems from potentially harmful effects of chemical pollutants. Although lagging behind applications targeted to human endpoints, metabolomics offers great potential in ecotoxicology. Indeed, the advantages of met...
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Hoffman, D.J.; Rattner, B.A.; Scheunert, I.; Korte, F.; Shore, Richard F.; Rattner, Barnett A.
2001-01-01
The purpose of this chapter is to provide an overview of the ecotoxicology of major classes of environmental contaminants, with respect to sources, environmental chemistry, most likely routes of exposure, potential bioaccumulation and biomagification, mechanisms of toxicity, and effects on potentially vulnerable species of mammalian wildlife. Major contaminants reviewed were selected on the basis of their use patterns, availability and potential toxicity to wild mammals. These included pesticides used in agroecosystems (organochlorines, organophosphorus and carbamate compounds, anticoagulants, herbicides and fungicides), various organic pollutants (chlorobenzenes, chlorophenols, polychlorinated biphenyls, dibenzodioxins and dibenzofurans, and polycyclic aromatic hydrocarbons), heavy metals (lead, mercury, and cadmium), agricultural drainwater mixtures, leachates and radionuclides. Many of the above aspects of ecotoxicology and contaminants will be expanded upon in subsequent chapters of this book as they relate to distinct mammalian species and potential risk.
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Zhou, Haidong; Ying, Tianqi; Wang, Xuelian; Liu, Jianbo
2016-01-01
Twelve selected pharmaceuticals including antibiotics, analgesics, antiepileptics and lipid regulators were analysed and detected in water samples collected from 18 sampling sections along the three main urban rivers in Yangpu District of Shanghai, China during four sampling campaigns. Besides, algal growth inhibition test was conducted to preliminarily assess the eco-toxicology induced by the target pharmaceuticals in the rivers. Mean levels for most of target compounds were generally below 100 ng/L at sampling sections, with the exception of caffeine and paracetamol presenting considerably high concentration. The detected pharmaceuticals in the urban rivers ranged from
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NASA Astrophysics Data System (ADS)
Zhou, Haidong; Ying, Tianqi; Wang, Xuelian; Liu, Jianbo
2016-10-01
Twelve selected pharmaceuticals including antibiotics, analgesics, antiepileptics and lipid regulators were analysed and detected in water samples collected from 18 sampling sections along the three main urban rivers in Yangpu District of Shanghai, China during four sampling campaigns. Besides, algal growth inhibition test was conducted to preliminarily assess the eco-toxicology induced by the target pharmaceuticals in the rivers. Mean levels for most of target compounds were generally below 100 ng/L at sampling sections, with the exception of caffeine and paracetamol presenting considerably high concentration. The detected pharmaceuticals in the urban rivers ranged from
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Bengtsson-Palme, Johan; Larsson, D G Joakim
2016-01-01
There are concerns that selection pressure from antibiotics in the environment may accelerate the evolution and dissemination of antibiotic-resistant pathogens. Nevertheless, there is currently no regulatory system that takes such risks into account. In part, this is due to limited knowledge of environmental concentrations that might exert selection for resistant bacteria. To experimentally determine minimal selective concentrations in complex microbial ecosystems for all antibiotics would involve considerable effort. In this work, our aim was to estimate upper boundaries for selective concentrations for all common antibiotics, based on the assumption that selective concentrations a priori need to be lower than those completely inhibiting growth. Data on Minimal Inhibitory Concentrations (MICs) were obtained for 111 antibiotics from the public EUCAST database. The 1% lowest observed MICs were identified, and to compensate for limited species coverage, predicted lowest MICs adjusted for the number of tested species were extrapolated through modeling. Predicted No Effect Concentrations (PNECs) for resistance selection were then assessed using an assessment factor of 10 to account for differences between MICs and minimal selective concentrations. The resulting PNECs ranged from 8 ng/L to 64 μg/L. Furthermore, the link between taxonomic similarity between species and lowest MIC was weak. This work provides estimated upper boundaries for selective concentrations (lowest MICs) and PNECs for resistance selection for all common antibiotics. In most cases, PNECs for selection of resistance were below available PNECs for ecotoxicological effects. The generated PNECs can guide implementation of compound-specific emission limits that take into account risks for resistance promotion. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Detection and Quantification of Graphene-Family Nanomaterials in the Environment
An increase in production of commercial products containing graphene-family nanomaterials (GFNs) has led to concern over their release into the environment. The fate and potential ecotoxicological effects of GFNs in the environment are currently unclear, partially due to the limi...
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Rattner, B.A.; Eisenreich, K.M.; Golden, N.H.; McKernan, M.A.; Hothem, R.L.; Custer, T.W.
2005-01-01
The Contaminant Exposure and Effects—Terrestrial Vertebrates (CEE-TV) database was developed to conduct simple searches for ecotoxicological information, examine exposure trends, and identify significant data gaps. The CEE-TV database contains 16,696 data records on free-ranging amphibians, reptiles, birds, and mammals residing in estuarine and coastal habitats of the Atlantic, Gulf, and Pacific coasts, Alaska, Hawaii, and the Great Lakes. Information in the database was derived from over 1800 source documents, representing 483 unique species (about 252,000 individuals), with sample collection dates spanning from 1884 to 2003. The majority of the records contain exposure data (generally contaminant concentrations) on a limited number (n = 209) of chlorinated and brominated compounds, cholinesterase-inhibiting pesticides, economic poisons, metals, and petroleum hydrocarbons, whereas only 9.3% of the records contain biomarker or bioindicator effects data. Temporal examination of exposure data provides evidence of declining concentrations of certain organochlorine pesticides in some avian species (e.g., ospreys, Pandion haliaetus), and an apparent increase in the detection and possibly the incidence of avian die-offs related to cholinesterase-inhibiting pesticides. To identify spatial data gaps, 11,360 database records with specific sampling locations were combined with the boundaries of coastal watersheds, and National Wildlife Refuge and National Park units. Terrestrial vertebrate ecotoxicological data were lacking in 41.9% of 464 coastal watersheds in the continental United States. Recent (1990–2003) terrestrial vertebrate contaminant exposure or effects data were available for only about half of the National Wildlife Refuge and National Park units in the geographic area encompassed by the database. When these data gaps were overlaid on watersheds exhibiting serious water quality problems and/or high vulnerability to pollution, 72 coastal watersheds, and 76 National Wildlife Refuge and 59 National Park units in the continental United States were found to lack recent terrestrial vertebrate ecotoxicology data. Delineation of data gaps in watersheds of concern can help prioritize monitoring in areas with impaired water quality and emphasize the need for comprehensive monitoring to gain a more complete understanding of coastal ecosystem health.
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Assessing the relevance of ecotoxicological studies for regulatory decision making.
Rudén, Christina; Adams, Julie; Ågerstrand, Marlene; Brock, Theo Cm; Poulsen, Veronique; Schlekat, Christian E; Wheeler, James R; Henry, Tala R
2017-07-01
Regulatory policies in many parts of the world recognize either the utility of or the mandate that all available studies be considered in environmental or ecological hazard and risk assessment (ERA) of chemicals, including studies from the peer-reviewed literature. Consequently, a vast array of different studies and data types need to be considered. The first steps in the evaluation process involve determining whether the study is relevant to the ERA and sufficiently reliable. Relevance evaluation is typically performed using existing guidance but involves application of "expert judgment" by risk assessors. In the present paper, we review published guidance for relevance evaluation and, on the basis of the practical experience within the group of authors, we identify additional aspects and further develop already proposed aspects that should be considered when conducting a relevance assessment for ecotoxicological studies. From a regulatory point of view, the overarching key aspect of relevance concerns the ability to directly or indirectly use the study in ERA with the purpose of addressing specific protection goals and ultimately regulatory decision making. Because ERA schemes are based on the appropriate linking of exposure and effect estimates, important features of ecotoxicological studies relate to exposure relevance and biological relevance. Exposure relevance addresses the representativeness of the test substance, environmental exposure media, and exposure regime. Biological relevance deals with the environmental significance of the test organism and the endpoints selected, the ecological realism of the test conditions simulated in the study, as well as a mechanistic link of treatment-related effects for endpoints to the protection goal identified in the ERA. In addition, uncertainties associated with relevance should be considered in the assessment. A systematic and transparent assessment of relevance is needed for regulatory decision making. The relevance aspects also need to be considered by scientists when designing, performing, and reporting ecotoxicological studies to facilitate their use in ERA. Integr Environ Assess Manag 2017;13:652-663. © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2016 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Rattner, B.A.; Ackerson, B.K.; Eisenreich, K.M.; McKernan, M.A.; Harmon, David
2006-01-01
The Biomonitoring of Environmental Status and Trends (BEST) Project of the U.S. Geological Survey (USGS) assesses the exposure and effects of environmental contaminants on select species and habitats in the United States. One of the many BEST Project activities entails the development of decision-support tools to assist in the identification of chemical threats to species and lands under the stewardship of the Department of the Interior. Although there are many ecotoxicological monitoring programs that focus on aquatic species and habitats, there are currently no large-scale efforts that are focused on terrestrial vertebrates in the United States. Nonetheless, organochlorine contaminants, metals, and new pollutants continue to pose hazards to terrestrial vertebrates at many spatial scales (ranging from small hazardous-waste-site point sources to entire watersheds). To evaluate and prioritize pollutant hazards for terrestrial vertebrates, a ?Contaminant Exposure and EffectsTerrestrial Vertebrates? (CEE-TV) database (www.pwrc.usgs.gov/contaminants-online) was developed. The CEE-TV database has been used to conduct simple searches for exposure and biological effects information for a given species or location, identification of temporal contaminant exposure trends, information gap analyses for national wildlife refuge and national park units, and ranking of terrestrial vertebrate ecotoxicological information needs based on data density and water quality problems. Despite widespread concerns about environmental contamination, during the past decade only about one-half of the coastal National Park units appear to have terrestrial vertebrate ecotoxicological data. Based upon known environmental contaminant hazards, it is recommended that regionalized monitoring programs or efforts focused on lands managed by the Department of the Interior should be undertaken to prevent serious natural resource problems.
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Wichmann, H; Kolb, M; Jopke, P; Schmidt, C; Alawi, M; Bahadir, M
2006-12-01
Two different waste disposal sites in Jordan were investigated in order to determine the environmental situation in context with waste disposal techniques. One landfill, located at Marka/Amman, had been closed about 25 years ago and covered with soil. Here, the waste had been actively open combusted and openings in the cover, still emitting smoke, indicated that waste was still smoldering inside the landfill's body. The second disposal site close to Ekeeder/Irbid is still operated. On this ground, the solid waste is not intentionally burned, although spontaneous fires frequently come up. Samples of waste, soil, and entrained dust were collected and analyzed. From the solid samples, respectively, their eluates, sum parameters, ecotoxicological effects as well as contents of elements/heavy metals and organic pollutants (PAH, PCDD/F) were determined. In general, the Ekeeder-samples were low-contaminated. The investigation of the Marka-samples showed higher contamination of the site's center, clearly being influenced by combustion processes. A significant contamination of the landfill's vicinity by its emissions could not be derived from the analytical data. Ecotoxicological investigations, applying a bio-test battery, revealed correlations with the sum parameters but not with the trace pollutants. Thus, the Marka-samples with the highest measured values of sum parameters caused adverse effects on three different test species, whereas other samples from Marka and Ekeeder had small or no effects. The results of these investigations depict the influence of different disposal techniques on the contamination situation of a landfill and they shall contribute to assess the conditions of other disposal sites in (semi)arid regions.
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Chapter 6: Ecotoxicology, Environmental Risk Assessment & Potential Impact on Human Health
This chapter examines potential risks posed by pharmaceuticals present in the aquatic environment to humans and aquatic life. We begin by describing the mechanisms by which pharmaceuticals enter the vertebrate body, produce effects and leave the body. Then we describe theoretical...
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The conservation of genetic diversity has emerged as one of the central issues in conservation biology. Although researchers in the areas of evolutionary biology, population management, and conservation biology routinely investigate genetic variability in natural populations, onl...
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PROTEOMICS IN ECOTOXICOLOGY: PROTEIN EXPRESSION PROFILING TO SCREEN CHEMICALS FOR ENDOCRINE ACTIVITY
Abstract for poster.
Current endocrine testing methods are animal intensive and lack the throughput necessary to screen large numbers of environmental chemicals for adverse effects. In this study, Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry... -
Oláh, Viktor; Hepp, Anna; Mészáros, Ilona
2016-05-01
In this study germination of Spirodela polyrhiza (L.) Schleiden (giant duckweed) turions was assessed under cadmium exposure to test applicability of a novel turion-based ecotoxicology method. Floating success of germinating turions, protrusion of the first and subsequent fronds as test endpoints were investigated and compared to results of standard duckweed growth inhibition tests with fronds of the same species. Our results indicate that turions can be used to characterize effects of toxic substances. Initial phase of turion germination (floating up and appearance of the first frond) was less sensitive to Cd treatments than the subsequent frond production. The calculated effective concentrations for growth rates in turion and normal frond tests were similar. Single frond area produced by germinating turions proved to be the most sensitive test endpoint. Single frond area and colony disintegration as additionally measured parameters in normal frond cultures also changed due to Cd treatments but the sensitivity of these parameters was lower than that of growth rates.
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New approach to the ecotoxicological risk assessment of artificial outdoor sporting grounds.
Krüger, O; Kalbe, U; Richter, E; Egeler, P; Römbke, J; Berger, W
2013-04-01
Artificial surfaces for outdoor sporting grounds may pose environmental and health hazards that are difficult to assess due to their complex chemical composition. Ecotoxicity tests can indicate general hazardous impacts. We conducted growth inhibition (Pseudokirchneriella subcapitata) and acute toxicity tests (Daphnia magna) with leachates obtained from batch tests of granular infill material and column tests of complete sporting ground assemblies. Ethylene propylene diene monomer rubber (EPDM) leachate showed the highest effect on Daphnia magna (EC(50) < 0.4% leachate) and the leachate of scrap tires made of styrene butadiene rubber (SBR) had the highest effect on P. subcapitata (EC(10) = 4.2% leachate; EC(50) = 15.6% leachate). We found no correlations between ecotoxicity potential of leachates and zinc and PAH concentrations. Leachates obtained from column tests revealed lower ecotoxicological potential. Leachates of column tests of complete assemblies may be used for a reliable risk assessment of artificial sporting grounds. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Comparison of Heavy Metal Uptake by Eisenia Foetida with That of other Common Earthworms.
1986-01-01
the ecotoxicological testing of industrial chemicals. An earthworm bioassay procedure developed at the Waterways Experiment Station (Vicksburg... ecotoxicological testing of industrial S-. chemicals (EEC Directive 79/81, 1984). Earthworms are known to exploit a wide range of ecological niches within...inhabiting, deep burrowing species, (Ude, 1885) ingesting predominantly mineral soil. Colonizing cultivated soil, gardens, pastures and woodland
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Chiral extrapolation of nucleon axial charge gA in effective field theory
NASA Astrophysics Data System (ADS)
Li, Hong-na; Wang, P.
2016-12-01
The extrapolation of nucleon axial charge gA is investigated within the framework of heavy baryon chiral effective field theory. The intermediate octet and decuplet baryons are included in the one loop calculation. Finite range regularization is applied to improve the convergence in the quark-mass expansion. The lattice data from three different groups are used for the extrapolation. At physical pion mass, the extrapolated gA are all smaller than the experimental value. Supported by National Natural Science Foundation of China (11475186) and Sino-German CRC 110 (NSFC 11621131001)
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Development of a decision support system to manage contamination in marine ecosystems.
Dagnino, A; Viarengo, A
2014-01-01
In recent years, contamination and its interaction with climate-change variables have been recognized as critical stressors in coastal areas, emphasizing the need for a standardized framework encompassing chemical and biological data into risk indices to support decision-making. We therefore developed an innovative, expert decision support system (Exp-DSS) for the management of contamination in marine coastal ecosystems. The Exp-DSS has two main applications: (i) to determine environmental risk and biological vulnerability in contaminated sites; and (ii) to support the management of waters and sediments by assessing the risk due to the exposure of biota to these matrices. The Exp-DSS evaluates chemical data, both as single compounds and as total toxic pressure of the mixture, to compare concentrations to effect-based thresholds (TELs and PELs). Sites are then placed into three categories of contamination: uncontaminated, mildly contaminated, and highly contaminated. In highly contaminated sites, effects on high-level ecotoxicological endpoints (i.e. survival and reproduction) are used to determine risk at the organism-population level, while ecological parameters (i.e. alterations in community structure and ecosystem functions) are considered for assessing effects on biodiversity. Changes in sublethal biomarkers are utilized to assess the stress level of the organisms in mildly contaminated sites. In Triad studies, chemical concentrations, ecotoxicological high-level effects, and ecological data are combined to determine the level of environmental risk in highly contaminated sites; chemical concentration and ecotoxicological sublethal effects are evaluated to determine biological vulnerability in mildly contaminated sites. The Exp-DSS was applied to data from the literature about sediment quality in estuarine areas of Spain, and ranked risks related to exposure to contaminated sediments from high risk (Huelva estuary) to mild risk (Guadalquivir estuary and Bay of Cadiz). A spreadsheet-based version of the Exp-DSS is available at the MEECE and DiSIT web sites (www.meece.eu and www.disit.unipmn.it). © 2013 Elsevier B.V. All rights reserved.
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Kresmann, Simon; Arokia, Arokia Hansel Rajan; Koch, Christoph; Sures, Bernd
2018-06-01
The use of biocides by industry, agriculture and households increased throughout the last two decades. Many new applications with known substances enriched the variety of biocidal pollution sources for the aquatic environment. While agriculture was the major source for a long time, leaching from building facades and preservation of personal care and cleaning products was identified as new sources in the last few years. With the different usage forms of biocidal products the complexity of legislative regulation increased as well. The requirements for risk assessment differ from one law to another and the potential risk of substances under different regulations might be underestimated. Still EC 50 and predicted no-effect concentration (PNEC) values gained from testing with different species are the core of environmental risk assessment, but ecotoxicological data is limited or lacking for many biocides. In this study the biocides widely used in facade coatings and household products terbutryn, octhilinone and methylisothiazolinone were tested with the Daphnia magna acute immobilisation assay, the neutral red uptake assay and the ethoxyresorufin-O-deethylase (EROD) assay, performed with rainbow trout liver (RTL-W1) cells. Further, the MTT assay with the ovarian cell line CHO-9 from Chinese hamster was used as mammalian model. Octhilinone induced the strongest effects with EC 50 values of 156μg/l in the D. magna assay, while terbutryn showed the weakest effects with 8390μg/l and methylisothiazolinone 513μg/l respectively. All other assays showed higher EC 50 values and thus only weak effects. EROD assays did not show any effects. With additional literature and database records PNEC values were calculated: terbutryn reached 0.003μg/l, octhilinone 0.05μg/l and methylisothiazolinone 0.5μg/l. Potential ecotoxicological risks of these biocides are discussed, considering environmental concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.
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Garcia-Käufer, M; Gartiser, S; Hafner, C; Schiwy, S; Keiter, S; Gründemann, C; Hollert, H
2015-11-01
The embryotoxic potential of three model sediment samples with a distinct and well-characterized pollutant burden from the main German river basins Rhine and Elbe was investigated. The Fish Embryo Contact Test (FECT) in zebrafish (Danio rerio) was applied and submitted to further development to allow for a comprehensive risk assessment of such complex environmental samples. As particulate pollutants are constructive constituents of sediments, they underlay episodic source-sink dynamics, becoming available to benthic organisms. As bioavailability of xenobiotics is a crucial factor for ecotoxicological hazard, we focused on the direct particle-exposure pathway, evaluating throughput-capable endpoints and considering toxicokinetics. Fish embryo and larvae were exposed toward reconstituted (freeze-dried) sediment samples on a microcosm-scale experimental approach. A range of different developmental embryonic stages were considered to gain knowledge of potential correlations with metabolic competence during the early embryogenesis. Morphological, physiological, and molecular endpoints were investigated to elucidate induced adverse effects, placing particular emphasis on genomic instability, assessed by the in vivo comet assay. Flow cytometry was used to investigate the extent of induced cell death, since cytotoxicity can lead to confounding effects. The implementation of relative toxicity indices further provides inter-comparability between samples and related studies. All of the investigated sediments represent a significant ecotoxicological hazard by disrupting embryogenesis in zebrafish. Beside the induction of acute toxicity, morphological and physiological embryotoxic effects could be identified in a concentration-response manner. Increased DNA strand break frequency was detected after sediment contact in characteristic non-monotonic dose-response behavior due to overlapping cytotoxic effects. The embryonic zebrafish toxicity model along with the in vivo comet assay and molecular biomarker analysis should prospectively be considered to assess the ecotoxicological potential of sediments allowing for a comprehensive hazard ranking. In order to elucidate mode of action, novel techniques such as flow cytometry have been adopted and proved to be valuable tools for advanced risk assessment and management.
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Awrahman, Zmnako A; Rainbow, Philip S; Smith, Brian D; Khan, Farhan R; Fialkowski, Wojciech
2016-09-01
Demonstration of an ecotoxicological effect of raised toxic metal bioavailabilities on benthic macroinvertebrate communities in contaminated freshwater streams typically requires the labour-intensive identification and quantification of such communities before the application of multivariate statistical analysis. A simpler approach is the use of accumulated trace metal concentrations in a metal-resistant biomonitor to define thresholds that indicate the presence of raised trace metal bioavailabilities causing ecotoxicological responses in populations of more metal-sensitive members of the community. We explore further the hypothesis that concentrations of toxic metals in larvae of species of the caddisfly genus Hydropsyche can be used to predict metal-driven ecotoxicological responses in more metal-sensitive mayflies, especially ephemerellid and heptageniid mayflies, in metal-contaminated rivers. Comparative investigation of two caddisflies, Hydropsyche siltalai and Hydropsyche angustipennis, from metal-contaminated rivers in Cornwall and Upper Silesia, Poland respectively, has provided preliminary evidence that this hypothesis is applicable across caddisfly species and contaminated river systems. Use of a combined toxic unit approach, relying on independent data sets, suggested that copper and probably also arsenic are the drivers of mayfly ecotoxicity in the River Hayle and the Red River in Cornwall, while cadmium, lead and zinc are the toxic agents in the Biala Przemsza River in Poland. This approach has great potential as a simple tool to detect the more subtle effects of mixed trace metal contamination in freshwater systems. An informed choice of suitable biomonitor extends the principle to different freshwater habitats over different ranges of severity of trace metal contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Feiner, Mona; Beggel, Sebastian; Geist, Juergen
2016-11-01
Long-term effect assessments in ecotoxicological investigations are important, yet there is a lack of suitable exposure systems for these experiments that can be used for riverine species. A cost-efficient miniature circulatory system was developed that was evaluated for its applicability in long-term exposures in 2 stream-dwelling species: brown trout (Salmo trutta) and an amphipod (Gammarus roeseli). In an egg-to-fry exposure of S. trutta, the toxicity of 2 reverse osmosis concentrates was investigated as examples. Control hatching rate of yolk sac fry was 75 ± 7% and thus complies with the Organisation for Economic Co-operation and Development validity criterion (≥66%). The reverse osmosis concentrates did not impair the hatching rate in any tested concentration. In G. roeseli, mortality rates remained below 20% during a 21-d cultivation, fulfilling the common validity criterion in ecotoxicological testing. Mortality was significantly lower when the species was fed with conditioned alder leaves instead of an artificial shrimp food. Finally, a toxicity test on G. roeseli using copper as the test substance revealed median lethal concentration (LC50) values of 156 μg/L after 96 h and 99 μg/L after 264 h, which is in line with literature findings using other accepted exposure units. In conclusion, the miniature circulatory system provides a novel and cost-efficient exposure system for long-term investigations on riverine species that may also be applicable for other species of fishes and macroinvertebrates. Environ Toxicol Chem 2016;35:2827-2833. © 2016 SETAC. © 2016 SETAC.
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Bioconcentration, bioaccumulation, and metabolism of pesticides in aquatic organisms.
Katagi, Toshiyuki
2010-01-01
The ecotoxicological assessment of pesticide effects in the aquatic environment should normally be based on a deep knowledge of not only the concentration of pesticides and metabolites found but also on the influence of key abiotic and biotic processes that effect rates of dissipation. Although the bioconcentration and bioaccumulation potentials of pesticides in aquatic organisms are conveniently estimated from their hydrophobicity (represented by log K(ow), it is still indispensable to factor in the effects of key abiotic and biotic processes on such pesticides to gain a more precise understanding of how they may have in the natural environment. Relying only on pesticide hydrophobicity may produce an erroneous environmental impact assessment. Several factors affect rates of pesticide dissipation and accumulation in the aquatic environment. Such factors include the amount and type of sediment present in the water and type of diet available to water-dwelling organisms. The particular physiological behavior profiles of aquatic organisms in water, such as capacity for uptake, metabolism, and elimination, are also compelling factors, as is the chemistry of the water. When evaluating pesticide uptake and bioconcentration processes, it is important to know the amount and nature of bottom sediments present and the propensity that the stuffed aquatic organisms have to absorb and process xenobiotics. Extremely hydrophobic pesticides such as the organochlorines and pyrethroids are susceptible to adsorb strongly to dissolved organic matter associated with bottom sediment. Such absorption reduces the bioavailable fraction of pesticide dissolved in the water column and reduces the probable ecotoxicological impact on aquatic organisms living the water. In contrast, sediment dweller may suffer from higher levels of direct exposure to a pesticide, unless it is rapidly degraded in sediment. Metabolism is important to bioconcentration and bioaccumulation processes, as is detoxification and bioactivation. Hydrophobic pesticides that are expected to be highly stored in tissues would not be bioconcentrated if susceptible to biotic transformation by aquatic organisms to more rapidly metabolized to hydrophilic entities are generally less toxic. By analogy, pesticides that are metabolized to similar entities by aquatic species surely are les ecotoxicologically significant. One feature of fish and other aquatic species that makes them more relevant as targets of environmental studies and of regulation is that they may not only become contaminated by pesticides or other chemicals, but that they constitute and important part of the human diet. In this chapter, we provide an overview of the enzymes that are capable of metabolizing or otherwise assisting in the removal of xenobiotics from aquatic species. Many studies have been performed on the enzymes that are responsible for metabolizing xenobiotics. In addition to the use of conventional biochemical methods, such studies on enzymes are increasingly being conducted using immunochemical methods and amino acid or gene sequences analysis. Such studies have been performed in algae, in some aquatic macrophytes, and in bivalva, but less information is available for other aquatic species such as crustacea, annelids, aquatic insecta, and other species. Although their catabolizing activity is often lower than in mammals, oxidases, especially cytochrome P450 enzymes, play a central role in transforming pesticides in aquatic organisms. Primary metabolites, formed from such initial enzymatic action, are further conjugated with natural components such as carbohydrates, and this aids removal form the organisms. The pesticides that are susceptible to abiotic hydrolysis are generally also biotically degraded by various esterases to from hydrophilic conjugates. Reductive transformation is the main metabolic pathway for organochlorine pesticides, but less information on reductive enzymology processes is available. The information on aquatic species, other than fish, that pertains to bioconcentration factors, metabolism, and elimination is rather limited in the literature. The kinds of basic information that is unavailable but is needed on important aquatic species includes biochemistry, physiology, position in food web, habitat, life cycle, etc. such information is very important to obtaining improved ecotoxicology risk assessments for many pesticides and other chemicals. More research attention on the behavior of pesticides in, and affect on many standard aquatic test species (e.g., daphnids, chironomids, oligochaetes and some bivalves) would particularly be welcome. In addition to improving ecotoxicology risk assessments on target species, such information would also assist in better delineating affects on species at higher trophic levels that are predaceous on the target species. There is also need for designing and employing more realistic approaches to measure bioconcentration and bioaccumulation, and ecotoxicology effects of pesticides in natural environment. The currently employed steady-state laboratory exposure studies are insufficient to deal with the complexity of parameters that control the contrasts to the abiotic processes of pesticide investigated under the strictly controlled conditions, each process is significantly affected in the natural environment not only by the site-specific chemistry of water and sediment but also by climate. From this viewpoint, ecotoxicological assessment should be conducted, together with the detailed analyses of abiotic processes, when higher-tier mesocosm studies are performed. Moreover, in-depth investigation is needed to better understand the relationship between pesticide residues in organisms and associated ecotoxicological endpoints. The usual exposure assessment is based on apparent (nominal) concentrations fo pesticides, and the residues of pesticides or their metabolites in the organisms are not considered in to the context of ecotoxicological endpoints. Therefore, more metabolic and tissue distribution information for terminal pesticide residues is needed for aquatic species both in laboratory settings and in higher-tier (microcosm, mesocosm) studies.
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Pro-apoptotic effect of fly ash leachates in hepatocytes of freshwater fish (Channa punctata Bloch).
Ali, Mehboob; Rahman, Shakilur; Rehman, Hasibur; Bhatia, Kanchan; Ansari, Rizwan A; Raisuddin, Sheikh
2007-02-01
The pro-apoptotic effect of fly ash leachates (FAL) was studied in the hepatocytes of an Indian freshwater fish, Channa punctata Bloch. Hepatocytes were exposed to different concentrations of '7-day' FAL for 24 and 48h and various parameters of apoptosis were studied using standardized procedures. FAL-induced apoptosis in hepatocytes was indicated by cytological examination, DNA fragmentation and DNA laddering. The induction in cytochrome-c release, caspases 3, 7, 10 and 9 activities and lactate dehydrogenase level provide mechanistic platform for FAL-induced apoptosis. Cytological examination showed an unambiguous apoptotic effect of ash leachates in fish hepatocytes. Exposed hepatocytes also showed increased production of H(2)O(2), superoxide ions and an increase in lipid peroxidation (LPO). The present study suggests a possible role of reactive oxygen species (ROS) in FAL-induced apoptosis in hepatocytes. Lactate dehydrogenase, LPO and apoptosis as biomarkers of cytotoxicity have recently been used for assessment of ecotoxicological impact of environmental chemicals. Our findings show that these biomarkers may also be used for evaluation of ecotoxicological impact of complex chemical mixture such as fly ash and its leachates.
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Mezzelani, M; Gorbi, S; Fattorini, D; d'Errico, G; Consolandi, G; Milan, M; Bargelloni, L; Regoli, F
2018-05-01
Non-steroidal anti-inflammatory drugs (NSAIDs) represent a growing concern for marine ecosystems due to their ubiquitous occurrence and documented adverse effects on non-target organisms. Despite the remarkable efforts to elucidate bioaccumulation and ecotoxicological potential under short-term conditions, limited and fragmentary information is available for chronic exposures. In this study bioavailability, molecular and cellular effects of diclofenac (DIC), ibuprofen (IBU) and ketoprofen (KET) were investigated in mussels Mytilus galloprovincialis exposed to the realistic environmental concentration of 2.5 μg/L for up to 60 days. Results indicated a significant accumulation of DIC and IBU but without a clear time-dependent trend; on the other hand, KET concentrations were always below the detection limit. Analyses of a large panel of molecular, biochemical and cellular biomarkers highlighted that all investigated NSAIDs caused alterations of immunological parameters, genotoxic effects, modulation of lipid metabolism and changes in cellular turn-over. This study provided the evidence of long-term ecotoxicological potential of NSAIDs, further unraveling the possible hazard for wild marine organisms. Copyright © 2018 Elsevier Ltd. All rights reserved.
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De Laender, Frederik; Janssen, Colin R
2013-07-01
One of the objectives of the European Union (EU) ecological risk assessment of chemicals (ERA) is to derive maximum environmental concentrations that are not expected to cause adverse ecological effects. To this end, related EU directives list protection goals as well as guidelines that should be used to reach these goals. It is generally accepted that the individual-level endpoints on which these guidelines are based do not correspond to the listed population- and ecosystem-level protection goals. In this article, we identify 5 research topics that are key to bridging this gap: 1) the refinement of population-level effects and recovery rates by explicitly taking into account competition and 2) predation, 3) the assessment of chemical effects on biodiversity, 4) the assessment of chemical stress on ecosystem functions and services, and 5) the quantification of the effects of chemical mixtures. In addition, we illustrate why an ecosystem perspective is needed to address these topics and to inform the risk assessment process. We propose the use of existing ecotoxicological community, food web, and ecosystem models to tackle these issues and discuss why new models are needed to predict chemical effects on biodiversity. Copyright © 2013 SETAC.
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An ecotoxicological approach for hazard identification of energy ash.
Stiernström, S; Hemström, K; Wik, O; Carlsson, G; Bengtsson, B-E; Breitholtz, M
2011-02-01
Within the EU, ash should be classified by its inherent hazardous effects under criterion H-14 (ecotoxic) in the Directive on waste (2008/98/EC). Today, however, there are no harmonized quantitative criterions for such a classification, but it is stated that biological test systems can be used. In this study seven ash materials were leached and characterized, both biologically and chemically. The objectives were to evaluate if (a) clear concentration-response relationships could be achieved for the selected toxicity tests (bacteria, algae, crustacean and fish), (b) some test(s) are generally more sensitive and (c) the toxic responses were consistent with the chemical analyzes. Interestingly, our results indicate that high concentrations of non-hazardous components (Ca, K) influenced the toxicity of almost all ash eluates, whereas hazardous components (e.g. Zn, Pb) only influenced the toxicity of the eluates ranked as most hazardous. If considering both hazardous and non-hazardous substances, the observed toxic responses were relatively consistent with the chemical analyzes. Our results further showed that the (sub)chronic tests were much more sensitive than the acute tests. However, the use of extrapolation factors to compensate for using the less sensitive acute tests will likely lead to either over- or underestimations of toxicity. Our recommendation is therefore that classification of waste according to H-14 should be based on (sub)chronic test data. Finally, given that treatment of the eluates prior to toxicity testing has a major significance on the concentration and speciation of released substances, further studies are needed in order to propose a relevant testing scheme. Copyright © 2010 Elsevier Ltd. All rights reserved.
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Ecotoxicological effects and risk assessment of pollutants
Until somewhat recently there was limited awareness about the impact of soils on human health, ecosystems, and economy. Only in the second half of the twenty century the world awaked for the poor condition of soils, and to its several threats (e.g. soil contamination), as well as...
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Tracing the Sources of Macrolide Antibiotics and Illicit Drugs into the Lower Colorado River Basin
A number of pharmaceuticals have been detected in surface waters across the United States. Antibiotics present in the environment can produce resistance in microorganisms, which could potentially have adverse effects on human health. In addition, while the ecotoxicological signif...
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Advances in the study of the environmental fate, transport, and ecotoxicological effects of engineered nanomaterials (ENMs) have been hampered by a lack of adequate techniques for the detection and quantification of ENMs at environmentally relevant concentrations in complex media...
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Fritsch, Clémentine; Cœurdassier, Michaël; Giraudoux, Patrick; Raoul, Francis; Douay, Francis; Rieffel, Dominique; de Vaufleury, Annette; Scheifler, Renaud
2011-01-01
Concepts and developments for a new field in ecotoxicology, referred to as “landscape ecotoxicology,” were proposed in the 1990s; however, to date, few studies have been developed in this emergent field. In fact, there is a strong interest in developing this area, both for renewing the concepts and tools used in ecotoxicology as well as for responding to practical issues, such as risk assessment. The aim of this study was to investigate the spatial heterogeneity of metal bioaccumulation in animals in order to identify the role of spatially explicit factors, such as landscape as well as total and extractable metal concentrations in soils. Over a smelter-impacted area, we studied the accumulation of trace metals (TMs: Cd, Pb and Zn) in invertebrates (the grove snail Cepaea sp and the glass snail Oxychilus draparnaudi) and vertebrates (the bank vole Myodes glareolus and the greater white-toothed shrew Crocidura russula). Total and CaCl2-extractable concentrations of TMs were measured in soils from woody patches where the animals were captured. TM concentrations in animals exhibited a high spatial heterogeneity. They increased with soil pollution and were better explained by total rather than CaCl2-extractable TM concentrations, except in Cepaea sp. TM levels in animals and their variations along the pollution gradient were modulated by the landscape, and this influence was species and metal specific. Median soil metal concentrations (predicted by universal kriging) were calculated in buffers of increasing size and were related to bioaccumulation. The spatial scale at which TM concentrations in animals and soils showed the strongest correlations varied between metals, species and landscapes. The potential underlying mechanisms of landscape influence (community functioning, behaviour, etc.) are discussed. Present results highlight the need for the further development of landscape ecotoxicology and multi-scale approaches, which would enhance our understanding of pollutant transfer and effects in ecosystems. PMID:21655187
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López-Gastey, J; Choucri, A; Robidoux, P Y; Sunahara, G I
2000-06-01
An innovative screening procedure has been developed to detect illicit toxic discharges in domestic septic tank sludge hauled to the Montreal Urban Community waste-water treatment plant. This new means of control is based on an integrative approach, using bioassays and chemical analyses. Conservative criteria are applied to detect abnormal toxicity with great reliability while avoiding false positive results. The complementary data obtained from toxicity tests and chemical analyses support the use of this efficient and easy-to-apply procedure. This study assesses the control procedure in which 231 samples were analyzed over a 30-month period. Data clearly demonstrate the deterrent power of an efficient control procedure combined with a public awareness campaign among the carriers. In the first 15 months of application, between January 1996 and March 1997, approximately 30% of the 123 samples analyzed showed abnormal toxicity. Between April 1997 and June 1998, that is, after a public hearing presentation of this procedure, this proportion dropped significantly to approximately 9% based on 108 analyzed samples. The results of a 30-month application of this new control procedure show the superior efficiency of the ecotoxicological approach compared with the previously used chemical control procedure. To be able to apply it effectively and, if necessary, to apply the appropriate coercive measures, ecotoxicological criteria should be included in regulatory guidelines.
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Caluwé, Michel; Dobbeleers, Thomas; Daens, Dominique; Blust, Ronny; Geuens, Luc; Dries, Jan
2017-04-01
Research has demonstrated that the feeding pattern of synthetic wastewater plays an important role in sludge characteristics during biological wastewater treatment. Although considerable research has been devoted to synthetic wastewater, less attention has been paid to industrial wastewater. In this research, three different feeding strategies were applied during the treatment of tank truck cleaning (TTC) water. This industry produces highly variable wastewaters that are often loaded with hazardous chemicals, which makes them challenging to treat with activated sludge (AS). In this study, it is shown that the feeding pattern has a significant influence on the settling characteristics. Pulse feeding resulted in AS with a sludge volume index (SVI) of 68 ± 15 mL gMLSS -1 . Slowly and continuously fed AS had to contend with unstable SVI values that fluctuated between 100 and 600 mL gMLSS -1 . These fluctuations were clearly caused by the feeding solution. The obtained settling characteristics are being supported by the microscopic analysis, which revealed a clear floc structure for the pulse fed AS. Ecotoxicological effluent assessment with bacteria, Crustacea and algae identified algae as the most sensitive organism for all effluents from all different reactors. Variable algae growth inhibitions were measured between the different reactors. The chemical and ecotoxicological effluent quality was comparable between the reactors.
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Buerge, Ignaz J; Buser, Hans-Rudolf; Poiger, Thomas; Müller, Markus D
2006-12-01
The two oxazaphosphorine compounds cyclophosphamide and ifosfamide are important cytostatic drugs used in the chemotherapy of cancer and in the treatment of autoimmune diseases. Their mechanism of action, involving metabolic activation and unspecific alkylation of nucleophilic compounds, accounts for genotoxic effects described in the literature and is reason for environmental concern. The occurrence and fate of cyclophosphamide and ifosfamide were studied in wastewater treatment plants (WWTPs) and surface waters in Switzerland, using a highly sensitive analytical method based on solid-phase extraction and liquid chromatography tandem mass spectrometry. The compounds were detected in untreated and treated wastewater at concentrations of <0.3-11 ng/L, which corresponded well with concentrations predicted from consumption data and typical renal excretion rates. Weekly loads determined in influent and effluent wastewater were comparable and suggested a high persistence in WWTPs. Furthermore, no degradation was observed in activated sludge incubation experiments within 24 h at concentrations of approximately 100 ng/L. Processes that may be relevant for elimination in natural waterbodies were studied with a set of incubation experiments in the laboratory. After extrapolation to natural conditions in surface waters, a slow dark-chemical degradation (half-lives on the order of years) is the most important transformation process. Degradation by photochemically formed HO* radicals may be of some relevance only in shallow, clear, and nitrate-rich waterbodies but could be further exploited for elimination of these compounds by advanced oxidation processes, i.e., in a treatment of hospital wastewater. In surface waters, concentrations ranged from < or =50 to 170 pg/L and were thus several orders of magnitude lower than the levels at which acute ecotoxicological effects have been reported in the literature (mg/L range). However, due to a lack of studies on chronic effects on aquatic organisms and data on occurrence and effects of metabolites, a final risk assessment cannot be made.
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Amacker, Nathalie; Mitchell, Edward A D; Ferrari, Benoît J D; Chèvre, Nathalie
2018-06-01
An ever-increasing diversity of potentially toxic chemical compounds are being developed and released into the environment as a result of human activities (e.g. agriculture, drugs, and cosmetics). Among these, pesticides have been shown to affect non-targeted wildlife since the 1960s. A range of ecotoxicological tests are used to assess the toxicity of pesticides on various model organisms. However most model organisms are metazoans, while the majority of Eukaryotes are unicellular microorganisms known as protists. Protists are ubiquitous organisms of key functional roles in all ecosystems but are so far little studied with respect to pesticide impact. To fill this gap, we developed a new ecotoxicological test based on Euglypha rotunda, a common soil amoeba, grown in culture flask with Escherichia coli as sole food source. We tested this assay with the herbicide S-metolachlor, which is known to affect cell division in seedling shoots and roots of weeds. Reproducible growth conditions were obtained for E. rotunda. The growth of E. coli was not affected by the herbicide. The growth of E. rotunda was affected by the herbicide in a non-linear way, growth being significantly reduced at ca. 15 μg/L, but not at 150 μg/L. Our results show the potential for using soil protists in ecotoxicology and adds to the growing body of evidence for non-linear impacts of pesticides on non-target organisms. With the acquisition of additional data, the protocol should be suitable for standard ecotoxicological tests. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Prokop, Zbyněk; Nečasová, Anežka; Klánová, Jana; Čupr, Pavel
2016-03-01
A novel approach was developed for rapid assessment of bioavailability and potential mobility of contaminants in soil. The response of the same test organism to the organic extract, water extract and solid phase of soil was recorded and compared. This approach was designed to give an initial estimate of the total organic toxicity (response to organic extractable fraction), as well as the mobile (response to water extract) and bioavailable fraction (response to solid phase) of soil samples. Eighteen soil samples with different levels of pollution and content of organic carbon were selected to validate the novel three-step ecotoxicological evaluation approach. All samples were chemically analysed for priority contaminants, including aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) and dichlordiphenyltrichloroethane (DDT). The ecotoxicological evaluation involved determination of toxicity of the organic, mobile and bioavailable fractions of soil to the test organism, bacterium Bacillus cereus. We found a good correlation between the chemical analysis and the toxicity of organic extract. The low toxicity of water extracts indicated low water solubility, and thus, low potential mobility of toxic contaminants present in the soil samples. The toxicity of the bioavailable fraction was significantly greater than the toxicity of water-soluble (mobile) fraction of the contaminants as deduced from comparing untreated samples and water extracts. The bioavailability of the contaminants decreased with increasing concentrations of organic carbon in evaluated soil samples. In conclusion, the three-step ecotoxicological evaluation utilised in this study can give a quick insight into soil contamination in context with bioavailability and mobility of the contaminants present. This information can be useful for hazard identification and risk assessment of soil-associated contaminants. Graphical Abstract New three-step ecotoxicological evaluation by using the same organism.
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Young, Brian Jonathan; Rizzo, Pedro Federico; Riera, Nicolás Iván; Torre, Virginia Della; López, Valeria Alejandra; Molina, Cecilia Denisse; Fernández, Florencia Estefanía; Crespo, Diana Cristina; Barrena, Raquel; Komilis, Dimitrios; Sánchez, Antoni
2016-08-01
Both raw and composted poultry manure is applied as soil amendment. The aims of this study were: (1) to develop phytotoxicity indexes for organic wastes and composts, and (2) to assess the correlation among phytotoxicity indexes, ecotoxicological endpoints and stability and physicochemical parameters during passive composting of poultry manure. Six 2-m(3) composting piles were constructed and four parameter groups (physicochemical and microbiological parameters, ecotoxicological endpoints, and biological activity) were determined at four sampling times during 92days. Extracts were used to carry out acute toxicity tests on Daphnia magna, Lactuca sativa and Raphanus sativus. Composting decreased average toxicity 22.8% for the 3 species and D. magna was the most sensitive species. The static respiration index decreased from 1.12 to 0.46mgO2gOMh(-1) whilst organic matter reduced by 64.1% at the end of the process. Escherichia coli colonies remained higher than values recommended by international guidelines. The D. magna immobilization test allowed the assessment of possible leachate or run-off toxicity. The new phytotoxicity indexes (RGIC0.8 and GIC80%), proposed in this study, as well as salinity, proved to be good maturity indicators. Hence, these phytotoxicity indexes could be implemented in monitoring strategies as useful ecotoxicological tools. Multivariate analyses demonstrated positive correlations between ecotoxicological endpoints (low toxicity) and biological activity (stability). These two parameter groups were associated at the final sampling time and showed negative correlations with several physicochemical parameters (organic and inorganic contents). The final poultry manure compost was rendered stable, but immature and, thus, unsuitable for soil amending. Copyright © 2016 Elsevier Ltd. All rights reserved.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Kelly, J.R.; Duke, T.W.; Harwell, M.A.
Potential effects of oil drilling-fluid discharges upon Thalassia seagrass ecosystems were examined to provide general insights and raise ecotoxicological issues relevant to problems of addressing a priori, ecolgical effects of anthropogenic actions. Microcosm experiments have demonstrated effects upon both autotrophic and heterotrophic species, as well as the processes of primary productivity and decomposition. Significant ecological changes may result from disturbance effects related to the physical presence of higher particle loads, in addition to effects resulting from toxic features of drilling fluids.
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Adverse Outcome Pathways (AOPs) describe toxicant effects as a sequential chain of causally linked events beginning with a molecular perturbation and culminating in an adverse outcome at an individual or population level. Strategies for developing AOPs are still evolving and dep...
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This report summarizes the comments made at a two-day independent scientific peer review meeting on the Agency's draft assessment of health and ecotoxicological effects of perchlorate, entitled Perchlorate Environmental Contamination: Toxicological Review and Risk Characteriza...
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de Lapuente, J; González-Linares, J; Pique, E; Borràs, M
2014-01-01
The introduction of chemical products into the environment can cause long-term effects on the ecosystems. Increasing efforts are being made to determine the extent of contamination in particularly affected areas using diverse methods to assess the ecotoxicological impact. We used a modified Frog Embrio Toxicity Assay-Xenopus method to determine the extent of toxicological load in different sample soils obtained near three municipal solid waste landfills in Catalonia (Spain). The results show that the Garraf landfill facility produces more embryotoxic damage to the surroundings, than the others ones: Can Mata landfill and Montferrer-Castellbó landfill. The aim of this work is to demonstrate how different management of complex sources of contamination as the controlled dumping sites can modulate the presence of toxics in the environment and their effects and through this, help determine the safer way to treat these wastes. To this effect some conceptual modifications have been made on the established American Society for Testing and Materials protocol. The validity of the new model, both as to model of calculation as to protocol, has been demonstrated in three different sites with complex sources of contamination.
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Sun, Hong-Qin; Du, Yang; Zhang, Zi-Yang; Jiang, Wen-Jing; Guo, Yan-Min; Lu, Xi-Wu; Zhang, Yi-Min; Sun, Li-Wei
2016-09-19
Benzophenone (BP) and N,N -diethyl-3-methylbenzamide (DEET) are two chemicals often used in personal care products (PCPs). There is a lack of systematic ecotoxicological evaluations about the two chemicals to aquatic organisms. In the present study, the acute toxic effects on Chlorella vulgaris , Daphnia Magana , and Brachydanio rerio were tested and the ecotoxicological risks were evaluated. For BP, the 96-h half-maximal effective concentration (EC 50 ) on C. vulgaris was 6.86 mg/L; the 24-h median lethal concentration (LC 50 ) on D. magana was 7.63 mg/L; the 96-h LC 50 on B. rerio was 14.73 mg/L. For DEET, those were 270.72 mg/L, 40.74 mg/L, and 109.67 mg/L, respectively. The mixture toxicity of BP and DEET, on C. vulgaris , D. magana , and B. rerio all showed an additive effect. The induced predicted no-effect concentrations (PNECs) for BP and DEET by assessment factor (AF) method are 0.003 mg/L and 0.407 mg/L, respectively. Both are lower than the concentrations detected from environment at present, verifying that BP and DEET are low-risk chemicals to the environment.
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Sun, Hong-Qin; Du, Yang; Zhang, Zi-Yang; Jiang, Wen-Jing; Guo, Yan-Min; Lu, Xi-Wu; Zhang, Yi-Min; Sun, Li-Wei
2016-01-01
Benzophenone (BP) and N,N-diethyl-3-methylbenzamide (DEET) are two chemicals often used in personal care products (PCPs). There is a lack of systematic ecotoxicological evaluations about the two chemicals to aquatic organisms. In the present study, the acute toxic effects on Chlorella vulgaris, Daphnia Magana, and Brachydanio rerio were tested and the ecotoxicological risks were evaluated. For BP, the 96-h half-maximal effective concentration (EC50) on C. vulgaris was 6.86 mg/L; the 24-h median lethal concentration (LC50) on D. magana was 7.63 mg/L; the 96-h LC50 on B. rerio was 14.73 mg/L. For DEET, those were 270.72 mg/L, 40.74 mg/L, and 109.67 mg/L, respectively. The mixture toxicity of BP and DEET, on C. vulgaris, D. magana, and B. rerio all showed an additive effect. The induced predicted no-effect concentrations (PNECs) for BP and DEET by assessment factor (AF) method are 0.003 mg/L and 0.407 mg/L, respectively. Both are lower than the concentrations detected from environment at present, verifying that BP and DEET are low-risk chemicals to the environment. PMID:27657095
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Ecotoxicological evaluation of diesel-contaminated soil before and after a bioremediation process.
Molina-Barahona, L; Vega-Loyo, L; Guerrero, M; Ramírez, S; Romero, I; Vega-Jarquín, C; Albores, A
2005-02-01
Evaluation of contaminated sites is usually performed by chemical analysis of pollutants in soil. This is not enough either to evaluate the environmental risk of contaminated soil nor to evaluate the efficiency of soil cleanup techniques. Information on the bioavailability of complex mixtures of xenobiotics and degradation products cannot be totally provided by chemical analytical data, but results from bioassays can integrate the effects of pollutants in complex mixtures. In the preservation of human health and environment quality, it is important to assess the ecotoxicological effects of contaminated soils to obtain a better evaluation of the healthiness of this system. The monitoring of a diesel-contaminated soil and the evaluation of a bioremediation technique conducted on a microcosm scale were performed by a battery of ecotoxicological tests including phytotoxicity, Daphnia magna, and nematode assays. In this study we biostimulated the native microflora of soil contaminated with diesel by adding nutrients and crop residue (corn straw) as a bulking agent and as a source of microorganisms and nutrients; in addition, moisture was adjusted to enhance diesel removal. The bioremediation process efficiency was evaluated directly by an innovative, simple phytotoxicity test system and the diesel extracts by Daphnia magna and nematode assays. Contaminated soil samples were revealed to have toxic effects on seed germination, seedling growth, and Daphnia survival. After biostimulation, the diesel concentration was reduced by 50.6%, and the soil samples showed a significant reduction in phytotoxicity (9%-15%) and Daphnia assays (3-fold), confirming the effectiveness of the bioremediation process. Results from our microcosm study suggest that in addition to the evaluation of the bioremediation processes efficiency, toxicity testing is different with organisms representative of diverse phylogenic levels. The integration of analytical, toxicological and bioremediation data is necessary to properly assess the ecological risk of bioremediation processes. (c) 2005 Wiley Periodicals, Inc.
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Toxicological impacts of antibiotics on aquatic micro-organisms: A mini-review.
Välitalo, Pia; Kruglova, Antonina; Mikola, Anna; Vahala, Riku
2017-05-01
Antibiotics are found globally in the environment at trace levels due to their extensive consumption, which raises concerns about the effects they can have on non-target organisms, especially environmental micro-organisms. So far the majority of studies have focused on different aspects of antibiotic resistance or on analyzing the occurrence, fate, and removal of antibiotics from hospital and municipal wastewaters. Little attention has been paid to ecotoxicological effects of antibiotics on aquatic micro-organisms although they play a critical role in most ecosystems and they are potentially sensitive to these substances. Here we review the current state of research on the toxicological impacts of antibiotics to aquatic micro-organisms, including proteobacteria, cyanobacteria, algae and bacteria commonly present in biological wastewater treatment processes. We focus on antibiotics that are poorly removed during wastewater treatment and thus end up in surface waters. We critically discuss and compare the available analytical methods and test organisms based on effect concentrations and identify the knowledge gaps and future challenges. We conclude that, in general, cyanobacteria and ammonium oxidizing bacteria are the most sensitive micro-organisms to antibiotics. It is important to include chronic tests in ecotoxicological assessment, because acute tests are not always appropriate in case of low sensitivity (for example for proteobacteria). However, the issue of rapid development of antibiotic resistance should be regarded in chronic testing. Furthermore, the application of other species of bacteria and endpoints should be considered in the future, not forgetting the mixture effect and bacterial community studies. Due to differences in the sensitivity of different test organisms to individual antibiotic substances, the application of several bioassays with varying test organisms would provide more comprehensive data for the risk assessment of antibiotics. Regardless of the growing concerns related to antibiotics in the environment, there are still evident knowledge gaps related to antibiotics, as there is only limited or no ecotoxicological data on many potentially harmful antibiotics. Copyright © 2017 Elsevier GmbH. All rights reserved.
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Development of ecotoxicology procedures for use in assessing health of coral reefs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davies, P.S.; Marubini, F.
1995-12-31
There is widespread concern over the apparent worldwide decline in the health of coral reefs. However, assessment methods, other than long-term monitoring, have not yet been attempted. To remedy this the authors are developing ecotoxicology procedures to assess the effects of water quality factors on the corals themselves. Because of the problems of working with large, attached organisms, the authors have concentrated on developing small clonal preparations from corals with both a branching and a massive growth-form. For branching corals, tips (`nubbins`) are removed, and the cut surface ground smooth before cementing to 30mm x 30mm acrylic squares. Cores, ormore » `explants`, 25mm in diameter are removed from massive corals and cemented into injection-moulded plastic cups, to protect the cut surfaces of the skeleton. Trays of up to 18 nubbins and explants may then be transferred to the reef, where they are affixed to previously installed concrete breeze blocks. They may then be retrieved as required to assess the effects of water quality upon them. For laboratory ecotoxicology experiments, the authors have devised a system of artificial lighting, using halide lamps, to grow coral nubbins and explants under controlled conditions. To test the effects of pollutants, the authors use measurements of respiration, photosynthesis and skeletal growth rate. Growth is measured by a very simple buoyant weighing procedure, which requires only an analytical laboratory balance, and an easily-constructed plastic box-shaped chamber. The method is sufficiently sensitive to measure growth over a 24 hour period in some fast-growing corals. The authors will describe the results of initial experiments, carried out at the Bellairs Research Institute, Barbados, on the effects of different levels of phosphate and nitrate in the seawater. For the first time, they are able to demonstrate the concentration-related decrease in growth rate associated with nitrate eutrophication.« less
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Adverse outcome pathways: a concise introduction for toxicologists
Vergauwen, Lucia; Hengstler, Jan G.; Angrish, Michelle; Whelan, Maurice
2018-01-01
Adverse outcome pathways are designed to provide a clear-cut mechanistic representation of critical toxicological effects that propagate over different layers of biological organization from the initial interaction of a chemical with a molecular target to an adverse outcome at the individual or population level. Adverse outcome pathways are currently gaining momentum, especially in view of their many potential applications as pragmatic tools in the fields of human toxicology, ecotoxicology and risk assessment. A number of guidance documents, issued by the Organization for Economic Cooperation and Development, as well as landmark papers, outlining best practices to develop, assess and use adverse outcome pathways, have been published in the last few years. The present paper provides a synopsis of the main principles related to the adverse outcome pathway framework for the toxicologist less familiar with this area, followed by two case studies relevant for human toxicology and ecotoxicology. PMID:28660287
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Coulon, Frédéric; Al Awadi, Mohammed; Cowie, William; Mardlin, David; Pollard, Simon; Cunningham, Colin; Risdon, Graeme; Arthur, Paul; Semple, Kirk T; Paton, Graeme I
2010-10-01
A six month field scale study was carried out to compare windrow turning and biopile techniques for the remediation of soil contaminated with bunker C fuel oil. End-point clean-up targets were defined by human risk assessment and ecotoxicological hazard assessment approaches. Replicate windrows and biopiles were amended with either nutrients and inocula, nutrients alone or no amendment. In addition to fractionated hydrocarbon analysis, culturable microbial characterisation and soil ecotoxicological assays were performed. This particular soil, heavy in texture and historically contaminated with bunker fuel was more effectively remediated by windrowing, but coarser textures may be more amendable to biopiling. This trial reveals the benefit of developing risk and hazard based approaches in defining end-point bioremediation of heavy hydrocarbons when engineered biopile or windrow are proposed as treatment option. Copyright (c) 2010 Elsevier Ltd. All rights reserved.
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Beta-blockers in the environment: part II. Ecotoxicity study.
Maszkowska, Joanna; Stolte, Stefan; Kumirska, Jolanta; Łukaszewicz, Paulina; Mioduszewska, Katarzyna; Puckowski, Alan; Caban, Magda; Wagil, Marta; Stepnowski, Piotr; Białk-Bielińska, Anna
2014-09-15
The increasing consumption of beta-blockers (BB) has caused their presence in the environment to become more noticeable. Even though BB are safe for human and veterinary usage, ecosystems may be exposed to these substances. In this study, three selected BB: propranolol, metoprolol and nadolol were subjected to ecotoxicity study. Ecotoxicity evaluation was based on a flexible ecotoxicological test battery including organisms, representing different trophic levels and complexity: marine bacteria (Vibrio fischeri), soil/sediment bacteria (Arthrobacter globiformis), green algae (Scenedesmus vacuolatus) and duckweed (Lemna minor). All the ecotoxicological studies were supported by instrumental analysis to measure deviation between nominal and real test concentrations. Based on toxicological data from the green algae test (S. vacuolatus) propranolol and metoprolol can be considered to be harmful to aquatic organisms. However, sorption explicitly inhibits the hazardous effects of BB, therefore the risks posed by these compounds for the environment are of minor importance. Copyright © 2014 Elsevier B.V. All rights reserved.
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Resilience in ecotoxicology: Toward a multiple equilibrium concept
Bundschuh, Mirco; Schulz, Ralf; Allen, Craig R.; Angeler, David G.
2017-01-01
The term resilience describes stress–response patterns across scientific disciplines. In ecology, advances have been made to clearly define resilience based on underlying mechanistic assumptions. Engineering resilience (rebound) is used to describe the ability of organisms to recover from adverse conditions (disturbances), which is termed the rate of recovery. By contrast, the ecological resilience definition considers a systemic change, that is, when ecosystems reorganize into a new regime following disturbance. Under this new regime, structural and functional aspects change considerably relative to the previous regime, without recovery. In this context, resilience is an emergent property of complex systems. In the present study, we argue that both definitions and uses are appropriate in ecotoxicology, and although the differences are subtle, the implications and uses are profoundly different. We discuss resilience concepts in ecotoxicology, where the prevailing view of resilience is engineering resilience from chemical stress. Ecological resilience may also be useful for describing systemic ecological changes because of chemical stress. We present quantitative methods that allow ecotoxicologists and risk managers to assess whether an ecosystem faces an impending regime shift or whether it has already undergone such a shift. We contend that engineering and ecological resilience help to distinguish ecotoxicological responses to chemical stressors mechanistically and thus have implications for theory, policy, and application.
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Mougin, Christian; Azam, Didier; Caquet, Thierry; Cheviron, Nathalie; Dequiedt, Samuel; Le Galliard, Jean-François; Guillaume, Olivier; Houot, Sabine; Lacroix, Gérard; Lafolie, François; Maron, Pierre-Alain; Michniewicz, Radika; Pichot, Christian; Ranjard, Lionel; Roy, Jacques; Zeller, Bernd; Clobert, Jean; Chanzy, André
2015-10-01
The infrastructure for Analysis and Experimentation on Ecosystems (AnaEE-France) is an integrated network of the major French experimental, analytical, and modeling platforms dedicated to the biological study of continental ecosystems (aquatic and terrestrial). This infrastructure aims at understanding and predicting ecosystem dynamics under global change. AnaEE-France comprises complementary nodes offering access to the best experimental facilities and associated biological resources and data: Ecotrons, seminatural experimental platforms to manipulate terrestrial and aquatic ecosystems, in natura sites equipped for large-scale and long-term experiments. AnaEE-France also provides shared instruments and analytical platforms dedicated to environmental (micro) biology. Finally, AnaEE-France provides users with data bases and modeling tools designed to represent ecosystem dynamics and to go further in coupling ecological, agronomical, and evolutionary approaches. In particular, AnaEE-France offers adequate services to tackle the new challenges of research in ecotoxicology, positioning its various types of platforms in an ecologically advanced ecotoxicology approach. AnaEE-France is a leading international infrastructure, and it is pioneering the construction of AnaEE (Europe) infrastructure in the field of ecosystem research. AnaEE-France infrastructure is already open to the international community of scientists in the field of continental ecotoxicology.
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Strong, James Asa; Elliott, Michael
2017-03-15
The reporting of ecological phenomena and environmental status routinely required point observations, collected with traditional sampling approaches to be extrapolated to larger reporting scales. This process encompasses difficulties that can quickly entrain significant errors. Remote sensing techniques offer insights and exceptional spatial coverage for observing the marine environment. This review provides guidance on (i) the structures and discontinuities inherent within the extrapolative process, (ii) how to extrapolate effectively across multiple spatial scales, and (iii) remote sensing techniques and data sets that can facilitate this process. This evaluation illustrates that remote sensing techniques are a critical component in extrapolation and likely to underpin the production of high-quality assessments of ecological phenomena and the regional reporting of environmental status. Ultimately, is it hoped that this guidance will aid the production of robust and consistent extrapolations that also make full use of the techniques and data sets that expedite this process. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Ecotoxicological effects on earthworms of fresh and aged nano-sized zero-valent iron (nZVI) in soil.
El-Temsah, Yehia S; Joner, Erik J
2012-09-01
Although nano-sized zero-valent iron (nZVI) has been used for several years for remediation of contaminated soils and aquifers, only a limited number of studies have investigated secondary environmental effects and ecotoxicity of nZVI to soil organisms. In this study we therefore measured the ecotoxicological effects of nZVI coated with carboxymethyl cellulose on two species of earthworms, Eisenia fetida and Lumbricus rubellus, using standard OECD methods with sandy loam and artificial OECD soil. Earthworms were exposed to nZVI concentrations ranging from 0 to 2000 mg nZVI kg soil(-1) added freshly to soil or aged in non-saturated soil for 30 d prior to exposure. Regarding avoidance, weight changes and mortality, both earthworm species were significantly affected by nZVI concentrations ≥500 mg kg(-1)soil. Reproduction was affected also at 100 mg nZVI kg(-1). Toxicity effects of nZVI were reduced after aging with larger differences between soils compared to non-aged soils. We conclude that doses ≥500 mg nZVI kg(-1) are likely to give acute adverse effects on soil organisms, and that effects on reproduction may occur at significantly lower concentrations. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Im, Jinwoo; Yang, Kyung; Jho, Eun Hea; Nam, Kyoungphile
2015-11-01
The effect of soil washing used for arsenic (As)-contaminated soil remediation on soil properties and bioavailability of residual As in soil is receiving increasing attention due to increasing interest in conserving soil qualities after remediation. This study investigates the effect of different washing solutions on bioavailability of residual As in soils and soil properties after soil washing. Regardless of washing solutions, the sequential extraction revealed that the residual As concentrations and the amount of readily labile As in soils were reduced after soil washing. However, the bioassay tests showed that the washed soils exhibited ecotoxicological effects - lower seed germination, shoot growth, and enzyme activities - and this could largely be attributed to the acidic pH and/or excessive nutrient contents of the washed soils depending on washing solutions. Overall, this study showed that treated soils having lower levels of contaminants could still exhibit toxic effects due to changes in soil properties, which highly depended on washing solutions. This study also emphasizes that data on the As concentrations, the soil properties, and the ecotoxicological effects are necessary to properly manage the washed soils for reuses. The results of this study can, thus, be utilized to select proper post-treatment techniques for the washed soils. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Cross-species extrapolation of toxicity data from limited surrogate test organisms to all wildlife with potential of chemical exposure remains a key challenge in ecological risk assessment. A number of factors affect extrapolation, including the chemical exposure, pharmacokinetic...
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Piva, Francesco; Ciaprini, Francesco; Onorati, Fulvio; Benedetti, Maura; Fattorini, Daniele; Ausili, Antonella; Regoli, Francesco
2011-04-01
Quality assessments are crucial to all activities related to removal and management of sediments. Following a multidisciplinary, weight of evidence approach, a new model is presented here for comprehensive assessment of hazards associated to polluted sediments. The lines of evidence considered were sediment chemistry, assessment of bioavailability, sub-lethal effects on biomarkers, and ecotoxicological bioassays. A conceptual and software-assisted model was developed with logical flow-charts elaborating results from each line of evidence on the basis of several chemical and biological parameters, normative guidelines or scientific evidence; the data are thus summarized into four specific synthetic indices, before their integration into an overall sediment hazard evaluation. This model was validated using European eels (Anguilla anguilla) as the bioindicator species, exposed under laboratory conditions to sediments from an industrial site, and caged under field conditions in two harbour areas. The concentrations of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and trace metals were much higher in the industrial compared to harbour sediments, and accordingly the bioaccumulation in liver and gills of exposed eels showed marked differences between conditions seen. Among biomarkers, significant variations were observed for cytochrome P450-related responses, oxidative stress biomarkers, lysosomal stability and genotoxic effects; the overall elaboration of these data, as those of standard ecotoxicological bioassays with bacteria, algae and copepods, confirmed a higher level of biological hazard for industrial sediments. Based on comparisons with expert judgment, the model presented efficiently discriminates between the various conditions, both as individual modules and as an integrated final evaluation, and it appears to be a powerful tool to support more complex processes of environmental risk assessment. Copyright © 2010 Elsevier Ltd. All rights reserved.
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Rodgher, Suzelei; Espíndola, Evaldo Luiz Gaeta; Lombardi, Ana Teresa
2010-08-01
The acute toxicity of metals to Daphnia similis was determined and compared to other daphnid species to evaluate the suitability of this organism in ecotoxicology bioassays. To verify the performance D. similis in toxicity tests, we also investigated the effect of Pseudokirchneriella subcapitata at 1 x 10(5) and 1 x 10(6) cells ml(-1) on Cd and Cr acute toxicity to the cladoceran. Daphnid neonates were exposed to a range of chromium and cadmium concentrations in the absence and presence of the algal cells. Metal speciation calculations using MINEQL(+) showed that total dissolved metal concentrations in zooplankton culture corresponded to 96.2% free Cd and 100% free Cr concentrations. Initial total dissolved metal concentrations were used for 48 h-LC(50) determination. LC(50) for D. similis was 5.15 x 10(-7) mol l(-1) dissolved Cd without algal cells, whereas with 1 x 10(5) cells ml(-1), it was significantly higher (7.15 x 10(-7) mol l(-1) dissolved Cd). For Cr, the 48 h-LC(50) value of 9.17 x 10(-7) mol l(-1) obtained for the cladoceran in tests with 1 x 10(6) cells ml(-1) of P. subcapitata was also significantly higher than that obtained in tests without algal cells (5.28 x 10(-7) mol l(-1) dissolved Cr). The presence of algal cells reduced the toxicity of metals to D. similis, as observed in other studies that investigated the effects of food on metal toxicity to standard cladocerans. Comparing our results to those of literature, we observed that D. similis is as sensitive to metals as other standardized Daphnia species and may serve as a potential test species in ecotoxicological evaluations.
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Biology, Management and Utilization of Common Reed Pharagnites australis.
1987-02-01
Vrije Universiteit Waterways Experiment Staticn Department of Ecology and Ecotoxicology Environmental Laboratory P.O. Box 7161 P.O. Box 631 1007 MC...Madelijn van der Werff Vrije Universiteit Department of Ecology and Ecotoxicology Amsterdam and John W. Simmers and Stratford H. Kay Waterways...lowing and cutting 67 5.2.4. Active regulation of the water table 68 5.5. Nature conservation 68 5.4. Reed cultivation 69 Z.4. 1. Reed harvest 69 6
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Zortéa, Talyta; Segat, Julia C; Maccari, Ana Paula; Sousa, José Paulo; Da Silva, Aleksandro S; Baretta, Dilmar
2017-04-01
This study aimed to evaluate the effect of veterinary pharmaceuticals (VPs) used to control endo- and ectoparasites in ruminants, on the survival and reproduction of the collembolan species Folsomia candida. Standard ecotoxicological tests were conducted in Tropical Artificial Soil and the treatments consisted of increasing dosages of four commercial products with different active ingredients: ivermectin, fipronil, fluazuron and closantel. Ecotoxicological effects were related to the class and mode of action of the different compounds. Fipronil and ivermectin were the most toxic compounds causing a significant reduction in the number of juveniles at the lowest doses tested (LOEC reprod values of 0.3 and 0.2 mg kg -1 of dry soil, respectively) and similar low EC 50 values (fipronil: 0.19 mg kg -1 dry soil, CL 95% 0.16-0.22; ivermectin: 0.43 mg kg -1 dry soil, CL 95% 0.09-0.77), although the effects observed in the former compound were possibly related to a low adult survival (LC 50 of 0.62 mg kg -1 dry soil; CL 95% : 0.25-1.06). For the latter compound no significant lethal effects were observed. Fluazuron caused an intermediate toxicity (EC 50 of 3.07 mg kg -1 dry soil, CL 95% : 2.26-3.87), and also here a decrease in adult survival could explain the effects observed at reproduction. Closantel, despite showing a significant reduction on the number of juveniles produced, no dose-response relationship nor effects higher than 50% were observed. Overall, all tested compounds, especially ivermectin, when present in soil even at sub-lethal concentrations, can impair the reproduction of collembolans and possibly other arthropods. However, the actual risk to arthropod communities should be further investigated performing tests under a more realistic exposure (e.g., by testing the dung itself as the contaminated matrix) and by deriving ecotoxicologically relevant exposure concentration in soil derived from the presence of cattle dung. Copyright © 2017 Elsevier Ltd. All rights reserved.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Cangialosi, Maria Vittoria; Puccia, Egidio; Mazzola, Antonio
2010-05-15
In this study, we have identified several ovarian steroids in Ciona with high similarity to vertebrate steroids and showed that cholesterol, corticosterone, dehydroepiandrosterone, estrone, estradiol-17beta, testosterone, pregnenolone, progesterone, have identical molecular spectra with vertebrate steroids. In addition, we have studied the effects of an endocrine disruptor (tributyltin: TBT) on these sex hormones and their precursors, ovarian morphology, and gene expression of some key enzymes in steroidogenic pathway in the ovary of Ciona. Ovarian specimens were cultured in vitro using different concentrations of TBT (10{sup -5}, 10{sup -4} and 10{sup -3} M). Ethanol was used as solvent control. Gene expression analysismore » was performed for adrenodoxin (ADREN) and adrenodoxin reductase (ADOX) (mediators of acute steroidogenesis) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD). These transcripts were detected and measured by quantitative (real-time) polymerase chain reaction (qPCR). Sex steroids and their precursors were identified and quantified by a gas chromatography-mass spectroscopy (GC-MS) method. Exposure of Ciona ovaries to TBT produced modulations (either increased or decreased) of sterols and sex steroid levels, whereas no significant differences in ADREN, ADOX or 17beta-HSD mRNA expression patterns were observed. Histological analysis shows that TBT produced several modifications on Ciona ovarian morphology that includes irregular outline of nuclear membrane, less compacted cytoplasm, in addition to test and granulosa cells that were detached from the oocyte membrane. Given that the ascidians represent very simple experimental models for the study of endocrine disruption by environmental contaminants, our findings provide excellent models for multiple identification and quantification of sex steroid and their precursors in biological samples exposed to endocrine-disrupting chemicals and for direct extrapolation of such effects across taxonomic groups and phyla. In addition, these results suggest that Cionaintestinalis may be a suitable species for molecular ecotoxicological studies and biomarker model for endocrine-disrupting effects in marine invertebrates.« less
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Fish full life cycle (FFLC) tests are increasingly required in the ecotoxicological assessment of endocrine active substances. However, FFLC tests have not been internationally standardized or validated, and it is currently unclear how such tests should best be designed to provid...
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A Standardized Soil Ecotoxicological Test Using Red Worms (Eisenia fetida).
ERIC Educational Resources Information Center
Paradise, Christopher J.
2001-01-01
Describes a simple, inexpensive test for soil contamination that can be used in a variety of courses to examine the effects of soil toxicity, to practice standardized laboratory procedures, to study experimental design and data analysis, or to investigate earthworm ecology. Presents background information along with details regarding equipment,…
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Chelinho, Sónia; Lopes, Isabel; Natal-da-Luz, Tiago; Domene, Xaxier; Nunes, Maria Edna Tenorio; Espíndola, Evaldo L G; Ribeiro, Rui; Sousa, Jose P
2012-02-01
The aim of the present study is to contribute an ecologically relevant assessment of the ecotoxicological effects of pesticide applications in agricultural areas in the tropics, using an integrated approach with information gathered from soil and aquatic compartments. Carbofuran, an insecticide/nematicide used widely on sugarcane crops, was selected as a model substance. To evaluate the toxic effects of pesticide spraying for soil biota, as well as the potential indirect effects on aquatic biota resulting from surface runoff and/or leaching, field and laboratory (using a cost-effective simulator of pesticide applications) trials were performed. Standard ecotoxicological tests were performed with soil (Eisenia andrei, Folsomia candida, and Enchytraeus crypticus) and aquatic (Ceriodaphnia silvestrii) organisms, using serial dilutions of soil, eluate, leachate, and runoff samples. Among soil organisms, sensitivity was found to be E. crypticus < E. andrei < F. candida. Among the aqueous extracts, mortality of C. silvestrii was extreme in runoff samples, whereas eluates were by far the least toxic samples. A generally higher toxicity was found in the bioassays performed with samples from the field trial, indicating the need for improvements in the laboratory simulator. However, the tool developed proved to be valuable in evaluating the toxic effects of pesticide spraying in soils and the potential risks for aquatic compartments. Copyright © 2011 SETAC.
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In situ microbiota distinguished primary anthropogenic stressor in freshwater sediments.
Xie, Yuwei; Floehr, Tilman; Zhang, Xiaowei; Xiao, Hongxia; Yang, Jianghua; Xia, Pu; Burton, G Allen; Hollert, Henner
2018-08-01
Conventional assessment and evaluation of sediment quality are based on laboratory-based ecotoxicological and chemical measurements with lack of concern for ecological relevance. Microbiotas in sediment are responsive to pollutants and can be used as alternative ecological indicators of sediment pollutants; however, the linkage between the microbial ecology and ecotoxicological endpoints in response to sediment contamination has been poorly evaluated. Here, in situ microbiotas from the Three Gorges Reservoir (TGR) area of the Yangtze River were characterized by DNA metabarcoding approaches, and then, changes of in situ microbiotas were compared with the ecotoxicological endpoint, aryl hydrocarbon receptor (AhR) mediated activity, and level of polycyclic aromatic hydrocarbons (PAHs) in sediments. PAHs and organic pollutant mixtures mediating AhR activity had different effects on the structures of microbiotas. Specifically, Shannon indices of protistan communities were negatively correlated with the levels of AhR mediated activity and PAHs. The sediment AhR activity was positively correlated with the relative abundance of prokaryotic Acetobacteraceae, but had a negative correlation with protistan Oxytrichidae. Furthermore, a quantitative classification model was built to predict the level of AhR activity based on the relative abundances of Acetobacteraceae and Oxytrichidae. These results suggested that in situ Protista communities could provide a useful tool for monitoring and assessing ecological stressors. The observed responses of microbial community provided supplementary evidence to support that the AhR-active pollutants, such as PAHs, were the primary stressors of the aquatic community in TGR area. Copyright © 2018 Elsevier Ltd. All rights reserved.
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NASA Technical Reports Server (NTRS)
Bauschlicher, Charles W., Jr.; Arnold, James O. (Technical Monitor)
1999-01-01
The atomization energy of Mg4 is determined using the MP2 and CCSD(T) levels of theory. Basis set incompleteness, basis set extrapolation, and core-valence effects are discussed. Our best atomization energy, including the zero-point energy and scalar relativistic effects, is 24.6+/-1.6 kcal per mol. Our computed and extrapolated values are compared with previous results, where it is observed that our extrapolated MP2 value is good agreement with the MP2-R12 value. The CCSD(T) and MP2 core effects are found to have the opposite signs.
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Ecotoxicology of Hexavalent Chromium in Freshwater Fish: A Critical Review
Velma, Venkatramreddy; Vutukuru, S.S.; Tchounwou, Paul B.
2010-01-01
Chromium (Cr) is a naturally occurring element found in rocks, animals, plants, and soil, predominantly in its insoluble trivalent form [Cr(III)]. Intense industrialization and other anthropogenic activities have led to the global occurrence of soluble Cr(VI), which is readily leached from soil to groundwater or surface water, in concentrations above permissible levels. The ecotoxicology of Cr(VI) is linked to its environmental persistence and the ability to induce a variety of adverse effects in biologic systems, including fish. In aquatic ecosystems, Cr(VI) exposure poses a significant threat to aquatic life. This paper reviews the fate and transport of Cr(VI) in the environment and its acute and chronic effects on fish. We also discuss Cr(VI) toxicity at the cellular, biochemical, and genetic levels. An attempt is made in this review to comprehend the staggered data on the toxic effects of Cr(VI) to various species of fish. Such data are extremely useful to the scientific community and public officials involved in health risk assessment and management of environmental contaminants as a guide to the best course of action to restore ecosystems and, in turn, to preserve human health. PMID:19658319
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Environmental Risk Assessment of Pharmaceutical Mixtures: Demands, Gaps, and Possible Bridges.
Backhaus, Thomas
2016-07-01
The ecotoxicological risk of pharmaceutical mixtures typically exceeds the risk of each individual compound, which calls specific attention to the fact that monitoring surveys routinely find complex pharmaceutical mixtures in various environmental compartments. However, although the body of evidence on the ecotoxicology of pharmaceutical mixtures is quite consistent, the current guidelines for the environmental risk assessment of pharmaceuticals often do not explicitly address mixture effects. Data availability and acceptable methods often limit such assessments. A tiered approach that begins with summing up individual risk quotients, i.e., the ratio between the predicted or measured environmental concentration and the predicted no effect concentration (PNEC) is therefore suggested in this paper, in order to improve the realism of the environmental risk assessment of pharmaceuticals. Additionally, the use of a mixture-specific assessment factor, as well as the classical mixture toxicity concepts of concentration addition and independent action is explored. Finally, specific attention is given to the exposure-based waiving of environmental risk assessments, as currently implemented in screening or pre-screening phases (tier 0 in Europe, categorical exclusion in the USA), since even low, individually non-toxic concentrations might combine to produce substantial mixture effects.
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Chemical and ecotoxicological evaluation of biochar produced from residues of biogas production.
Stefaniuk, Magdalena; Oleszczuk, Patryk; Bartmiński, Piotr
2016-11-15
Analyses were carried out for biochars produced at three temperatures of pyrolysis (400, 600 and 800°C) from solid residue from biogas production (RBP). Separated and non-separated RBP from biogas plants employing different biogas production conditions were pyrolyzed. The contents of heavy metals and polycyclic aromatic hydrocarbons (PAHs) (16 PAH US EPA) were analyzed in biochars. The analyses showed that with an increased pyrolysis temperature, there was an increase in the contents of PAHs and of certain heavy metals (Cr, Cu, Cd, Pb and Mn). In the ecotoxicological tests, it was noted that the effect depended on the temperature of pyrolysis and on the feedstock from which the biochar was produced. The least harmful effect on the test organisms was from biochar produced by separated RBP in a biogas plant operating in mesophilic conditions. The most negative effect on the test organisms was characteristic of biochar produced from non-separated mesophilic RBP. This study shows that the main factors determining the level of toxicity of biochars produced from RBP towards various living organisms are both the method of feedstock production and the temperature at which the process of pyrolysis is conducted. Copyright © 2016 Elsevier B.V. All rights reserved.
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Potthoff, Annegret; Oelschlägel, Kathrin; Schmitt-Jansen, Mechthild; Rummel, Christoph Daniel; Kühnel, Dana
2017-05-01
The presence of microplastic (MP) in the aquatic environment is recognized as a global-scale pollution issue. Secondary MP particles result from an ongoing fragmentation process governed by various biotic and abiotic factors. For a reliable risk assessment of these MP particles, knowledge about interactions with biota is needed. However, extensive testing with standard organisms under reproducible laboratory conditions with well-characterized MP suspensions is not available yet. As MP in the environment represents a mixture of particles differing in properties (e.g., size, color, polymer type, surface characteristics), it is likely that only specific particle fractions pose a threat towards organisms. In order to assign hazardous effects to specific particle properties, these characteristics need to be analyzed. As shown by the testing of particles (e.g. nanoparticles), characteristics other than chemical properties are important for the emergence of toxicity in organisms, and parameters such as surface area or size distribution need consideration. Therefore, the use of "well-defined" particles for ecotoxicological testing (i.e., standard particles) facilitates the establishment of causal links between physical-chemical properties of MP particles and toxic effects in organisms. However, the benefits of well-defined particles under laboratory conditions are offset by the disadvantage of the unknown comparability with MP in the environment. Therefore, weathering effects caused by biological, chemical, physical or mechanical processes have to be considered. To date, the characterization of the progression of MP weathering based on powder and suspension characterization methods is in its infancy. The aim of this commentary is to illustrate the prerequisites for testing MP in the laboratory from 3 perspectives: (i) knowledge of particle properties; (ii) behavior of MP in test setups involving ecotoxicological test organisms; and (iii) accordingly, test conditions that may need adjustment. Only under those prerequisites will reliable hazard assessment of MP be feasible. Integr Environ Assess Manag 2017;13:500-504. © 2017 SETAC. © 2017 SETAC.
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Resilience in ecotoxicology: Toward a multiple equilibrium concept.
Bundschuh, Mirco; Schulz, Ralf; Schäfer, Ralf B; Allen, Craig R; Angeler, David G
2017-10-01
The term resilience describes stress-response patterns across scientific disciplines. In ecology, advances have been made to clearly define resilience based on underlying mechanistic assumptions. Engineering resilience (rebound) is used to describe the ability of organisms to recover from adverse conditions (disturbances), which is termed the rate of recovery. By contrast, the ecological resilience definition considers a systemic change, that is, when ecosystems reorganize into a new regime following disturbance. Under this new regime, structural and functional aspects change considerably relative to the previous regime, without recovery. In this context, resilience is an emergent property of complex systems. In the present study, we argue that both definitions and uses are appropriate in ecotoxicology, and although the differences are subtle, the implications and uses are profoundly different. We discuss resilience concepts in ecotoxicology, where the prevailing view of resilience is engineering resilience from chemical stress. Ecological resilience may also be useful for describing systemic ecological changes because of chemical stress. We present quantitative methods that allow ecotoxicologists and risk managers to assess whether an ecosystem faces an impending regime shift or whether it has already undergone such a shift. We contend that engineering and ecological resilience help to distinguish ecotoxicological responses to chemical stressors mechanistically and thus have implications for theory, policy, and application. Environ Toxicol Chem 2017;36:2574-2580. © 2017 SETAC. © 2017 SETAC.
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Martín, J; Camacho-Muñoz, D; Santos, J L; Aparicio, I; Alonso, E
2012-11-15
The occurrence of sixteen pharmaceutically active compounds in influent and effluent wastewater and in primary, secondary and digested sludge in one-year period has been evaluated. Solid-water partition coefficients (Kd) were calculated to evaluate the efficiency of removal of these compounds from wastewater by sorption onto sludge. The ecotoxicological risk to aquatic and terrestrial ecosystems, due to wastewater discharges to the receiving streams and to the application of digested sludge as fertilizer onto soils, was also evaluated. Twelve of the pharmaceuticals were detected in wastewater at mean concentrations from 0.1 to 32 μg/L. All the compounds found in wastewater were also found in sewage sludge, except diclofenac, at mean concentrations from 8.1 to 2206 μg/kg dm. Ibuprofen, salicylic acid, gemfibrozil and caffeine were the compounds at the highest concentrations. LogKd values were between 1.17 (naproxen) and 3.48 (carbamazepine). The highest ecotoxicological risk in effluent wastewater and digested sludge is due to ibuprofen (risk quotient (RQ): 3.2 and 4.4, respectively), 17α-ethinylestradiol (RQ: 12 and 22, respectively) and 17β-estradiol (RQ: 12 and 359, respectively). Ecotoxicological risk after wastewater discharge and sludge disposal is limited to the presence of 17β-estradiol in digested-sludge amended soil (RQ: 2.7). Copyright © 2012 Elsevier B.V. All rights reserved.
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Using soil health to assess ecotoxicological impacts of pollutants on soil microflora.
Bécaert, Valérie; Deschênes, Louise
2006-01-01
Microorganisms are essential for a properly functioning soil ecosystem. However, few methods allow an ecotoxicological evaluation of pollutant impact on the soil microbial community. This review proposes the use of the concept of soil health as an ecotoxicological evaluation tool for soil microflora. Initially limited to sustainable agriculture, the concept of soil health is now being applied to novel situations including contaminated and remediated soils. A large amount of work has been published in the last few decades on soil health indicators, and a review of the most relevant studies is presented here. The most cited work is that of the S-5518 committee set up in 1997 by the Soil Science Society of America (SSSA), which proposed to define soil quality as being "the capacity of a soil to function within the limits of an ecosystem, to support biological production, to maintain environmental quality and to support fauna and flora health." The soil health indicators reviewed here are the ones based on this definition because it relates well to sustainability and durability of the soil functions. Several indicators proposed in these studies could be employed in the evaluation of the ecotoxicological impact of pollutants on the soil microbial community, including microbial diversity, microbial activity, and functional stability. However, research is still required to unify the concept, to set threshold values, and to standardize methodologies.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Sparks, R.B.; Aydogan, B.
In the development of new radiopharmaceuticals, animal studies are typically performed to get a first approximation of the expected radiation dose in humans. This study evaluates the performance of some commonly used data extrapolation techniques to predict residence times in humans using data collected from animals. Residence times were calculated using animal and human data, and distributions of ratios of the animal results to human results were constructed for each extrapolation method. Four methods using animal data to predict human residence times were examined: (1) using no extrapolation, (2) using relative organ mass extrapolation, (3) using physiological time extrapolation, andmore » (4) using a combination of the mass and time methods. The residence time ratios were found to be log normally distributed for the nonextrapolated and extrapolated data sets. The use of relative organ mass extrapolation yielded no statistically significant change in the geometric mean or variance of the residence time ratios as compared to using no extrapolation. Physiologic time extrapolation yielded a statistically significant improvement (p < 0.01, paired t test) in the geometric mean of the residence time ratio from 0.5 to 0.8. Combining mass and time methods did not significantly improve the results of using time extrapolation alone. 63 refs., 4 figs., 3 tabs.« less
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Ming-Ch'eng Adams, Clare Isabel; Baker, Joel E; Kjellerup, Birthe V
2016-07-01
Prediction of vertebrate health effects originating from persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) has remained a challenge for decades thus making the identification of bioindicators difficult. POPs are predominantly present in soil and sediment, where they adhere to particles due to their hydrophobic characteristics. Animals inhabiting soil and sediment can be exposed to PCBs via dermal exposure while others may obtain PCBs through contaminated trophic interaction. Freshwater turtles can serve as bioindicators due to their strong site fidelity, longevity and varied diet. Previous research observed the health effects of PCBs on turtles such as decreased bone mass, changed sexual development and decreased immune responses through studying both contaminated sites along with laboratory experimentation. Higher deformity rates in juveniles, increased mortality and slower growth have also been observed. Toxicological effects of PCBs vary between species of freshwater turtles and depend on the concertation and configuration of PCB congeners. Evaluation of ecotoxicological effects of PCBs in non-endangered turtles could provide important knowledge about the health effects of endangered turtle species thus inform the design of remediation strategies. In this review, the PCB presence in freshwater turtle habitats and the ecotoxicological effects were investigated with the aim of utilizing the health status to identify areas of focus for freshwater turtle conservation. Copyright © 2016 Elsevier Ltd. All rights reserved.
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NASA Technical Reports Server (NTRS)
Darden, C. M.
1984-01-01
A method for analyzing shock coalescence which includes three dimensional effects was developed. The method is based on an extension of the axisymmetric solution, with asymmetric effects introduced through an additional set of governing equations, derived by taking the second circumferential derivative of the standard shock equations in the plane of symmetry. The coalescence method is consistent with and has been combined with a nonlinear sonic boom extrapolation program which is based on the method of characteristics. The extrapolation program, is able to extrapolate pressure signatures which include embedded shocks from an initial data line in the plane of symmetry at approximately one body length from the axis of the aircraft to the ground. The axisymmetric shock coalescence solution, the asymmetric shock coalescence solution, the method of incorporating these solutions into the extrapolation program, and the methods used to determine spatial derivatives needed in the coalescence solution are described. Results of the method are shown for a body of revolution at a small, positive angle of attack.
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2011-08-15
toxicity tests involving lethal and sublethal endpoints were conducted on sediments amended with apatite, organoclay, chitin , or acetate, with the polychaete...the test organisms. Chitin and acetate, however, repetitively resulted in adverse effects on survival and/or adverse or positive effects on organism...dissolved oxygen concentration, for chitin and acetate, respectively) as a result of the microbial breakdown of the amendments. For N. arenaceodentata
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Lapa, N; Barbosa, R; Lopes, M H; Mendes, B; Abelha, P; Boavida, D; Gulyurtlu, I; Oliveira, J Santos
2007-08-17
In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub-products of such type of thermal processes.
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Cold storage of Acartia tonsa eggs: a practical use in ecotoxicological studies.
Vitiello, V; Zhou, C; Scuderi, A; Pellegrini, D; Buttino, I
2016-07-01
The calanoid copepod Acartia tonsa has been recommended as a marine organism for ecotoxicological tests due to its wide distribution, short life cycle and high productivity. This species is used in acute and chronic toxicity tests to assess water and sediment quality; egg hatching success and the survival of the first larval stages are considered endpoints. Toxicity test protocols require a large number of organisms and an appropriate culture system. Eggs stored under conditions that delay hatching could ensure sufficient quantities of biological materials for ecotoxicological tests. In the current study early-spawned eggs were stored at 3 °C (±1) up to 240 days and their hatching success was evaluated on a monthly basis. Our results showed that the percentage of hatching success for eggs stored for 30 days was >80 % and decreased by about 8 % for every 20 days of storage, up to 120 days. A further increase of time in cold storage brought about a significant reduction, in statistical term, of hatching success compared with the control group (43.69 ± 22.19 %). Almost 50 % of eggs hatched or died during the cold storage period, with more than 80 % lost after periods longer than 150 days. To verify the suitability of stored eggs for toxicity test, 48 h acute tests were performed using nickel chloride as a referent toxicant. Eggs stored for 30, 60, 90 and 120 days gave EC50 values ranging from 0.130 to 0.221 mg L(-1), similar to the value recorded for early-spawned eggs, suggesting that these eggs can be used for ecotoxicological tests. Our results open new possibilities for a wider use of the Mediterranean strain of A. tonsa copepod for ecotoxicological tests.
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Fossi, Maria Cristina; Baini, Matteo; Panti, Cristina; Galli, Matteo; Jiménez, Begoña; Muñoz-Arnanz, Juan; Marsili, Letizia; Finoia, Maria Grazia; Ramírez-Macías, Dení
2017-09-01
The whale shark (Rhincodon typus) is an endangered species that may be exposed to micro- and macro-plastic ingestion as a result of their filter-feeding activity, particularly on the sea surface. In this pilot project we perform the first ecotoxicological investigation on whale sharks sampled in the Gulf of California exploring the potential interaction of this species with plastic debris (macro-, micro-plastics and related sorbed contaminants). Due to the difficulty in obtaining stranded specimens of this endangered species, an indirect approach, by skin biopsies was used for the evaluation of the whale shark ecotoxicological status. The levels of organochlorine compounds (PCBs, DDTs), polybrominated diphenyl ethers (PBDEs) plastic additives, and related biomarkers responses (CYP1A) were investigated for the first time in the whale shark. Twelve whale shark skin biopsy samples were collected in January 2014 in La Paz Bay (BCS, Mexico) and a preliminary investigation on microplastic concentration and polymer composition was also carried out in seawater samples from the same area. The average abundance pattern for the target contaminants was PCBs>DDTs>PBDEs>HCB. Mean concentration values of 8.42ng/g w.w. were found for PCBs, 1.31ng/g w.w. for DDTs, 0.29ng/g w.w. for PBDEs and 0.19ng/g w.w. for HCB. CYP1A-like protein was detected, for the first time, in whale shark skin samples. First data on the average density of microplastics in the superficial zooplankton/microplastic samples showed values ranging from 0.00items/m 3 to 0.14items/m 3 . A focused PCA analysis was performed to evaluate a possible correlation among the size of the whale sharks, contaminants and CYP1A reponses. Further ecotoxicological investigation on whale shark skin biopsies will be carried out for a worldwide ecotoxicological risk assessment of this endangerd species. Copyright © 2017 Elsevier Inc. All rights reserved.
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Bernardo, Maria S; Lapa, N; Barbosa, R; Gonçalves, M; Mendes, B; Pinto, F; Gulyurtlu, I
2009-07-15
A mixture of 70% (w/w) pine biomass and 30% (w/w) plastics (mixture of polypropylene, polyethylene, and polystyrene) was subjected to pyrolysis at 400 degrees C, for 15 min, with an initial pressure of 40 MPa. Part of the solid residue produced was subjected to extraction with dichloromethane (DCM). The extracted residue (residue A) and raw residue (residue B) were analyzed by weight loss combustion and submitted to the leaching test ISO/TS 21268-2 using two different leachants: DCM (0.2%, v/v) and calcium chloride (0.001 mol/L). The concentrations of the heavy metals Cd, Cr, Ni, Zn, Pb and Cu were determined in the eluates and in the two residues. The eluates were further characterized by determining their pH and the concentrations of benzene, toluene, ethylbenzene and xylenes (BTEX). The presence of other organic contaminants in the eluates was qualitatively evaluated by gas chromatography, coupled with mass spectrometry. An ecotoxicological characterization was also performed by using the bio-indicator Vibrio fischeri. The chemical and ecotoxicological results were analyzed according to the French proposal of Criteria on the Evaluation Methods of Waste Ecotoxicity (CEMWE). Residue A was not considered to be ecotoxic by the ecotoxicological criterion (EC(50) (30 min) >or=10%), but it was considered to be ecotoxic by the chemical criterion (Ni>or=0.5mg/L). Residue B was considered to be ecotoxic by the ecotoxicological criterion: EC(50) (30 min)
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Campbell, Kym Rouse; Campbell, Todd S
2002-05-01
Reptiles, specifically lizards and snakes, usually are excluded from environmental contamination studies and ecological risk assessments. This brief summary of available lizard and snake environmental contaminant data is presented to assist in the development of priorities for lizard and snake ecotoxicology. Most contaminant studies were not conducted recently, list animals found dead or dying after pesticide application, report residue concentrations after pesticide exposure, compare contaminant concentrations in animals from different areas, compare residue concentrations found in different tissues and organs, or compare changes in concentrations over time. The biological significance of the contaminant concentrations is rarely studied. A few recent studies, especially those conducted on modern pesticides, link the contaminant effects with exposure concentrations. Nondestructive sampling techniques for determining organic and inorganic contaminant concentrations in lizards and snakes recently have been developed. Studies that relate exposure, concentration, and effects of all types of environmental contaminants on lizards and snakes are needed. Because most lizards eat insects, studies on the exposure, effects, and accumulation of insecticides in lizards, and their predators, should be a top priority. Because all snakes are upper-trophic-level carnivores, studies on the accumulation and effects of contaminants that are known to bioaccumulate or biomagnify up the food chain should be the top priority.
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Palma, P; Matos, C; Alvarenga, P; Köck-Schulmeyer, M; Simões, I; Barceló, D; López de Alda, M J
2018-09-01
The objective of the study was to assess the integrated use of macroinvertebrate indexes and ecotoxicological parameters in the evaluation of the ecological status of a temporary stream with a strong agricultural influence. Water quality was analysed at two sampling sites along the stream, considering: chemical supporting parameters; hazardous substances (pesticides); benthic macroinvertebrate communities, through quality (Iberian Biological Monitoring Working Party and Iberian Average Score Per Taxon) and multi-metric indices (Southern Portuguese Index of Invertebrates and Ecological Quality Ratio); and ecotoxicological responses using lethal and sub-lethal bioassays. The water chemical characterization showed high levels of organic matter and nutrients, mainly in the dry period ((biochemical oxygen demand (BOD 5 ): 18.5-25.5mgL -1 , chemical oxygen demand (COD): 60.8-193.7mgL -1 ; total phosphorus (TP): 0.17-0.33mgL -1 )), which may compromise the support of biological life. In accordance with the physicochemical results, the stream had an ecological status less than good. Of the 25 pesticides analysed, only five, namely terbuthylazine, 2-methyl-chlorophenoxyacetic acid, bentazone, mecoprop and metolachlor were quantified. In general, the concentrations of pesticides detected were low, except at the source of the stream in January 2012 (sum of pesticides 2.29μgL -1 ), mainly due to the concentration of bentazone (1.77μgL -1 ), both values surpassing the European Commission threshold values. The analysis of benthic macroinvertebrates showed low levels of abundance and family diversity, with communities dominated by resistant groups to organic pollution and pesticides, such as the Chironomidae family. In general, the reproduction ecotoxicological results showed a very marked decrease in the number of juveniles per female. The Spearman correlation identified pesticides, namely MCPA (R=-0.89; p<0.05), as the main responsible for the observed effect. The results showed the linearity and complementarity of the two groups of biological responses, allowing to cover the interactions between the ecosystem's species and the different types of pollutants. Copyright © 2018 Elsevier B.V. All rights reserved.
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The US Environmental Protection Agency is a regulatory agency of the federal government whose mission it is to protect human health and to safeguard the natural environment -- air, water, land -- upon which life depends. The EPA has several Program and Regional Offices that for...
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A framework for predicting impacts on ecosystem services from (sub)organismal responses to chemicals
Valery E. Forbes; Chris J. Salice; Bjorn Birnir; Randy J.F. Bruins; Peter Calow; Virginie Ducrot; Nika Galic; Kristina Garber; Bret C. Harvey; Henriette Jager; Andrew Kanarek; Robert Pastorok; Steve F. Railsback; Richard Rebarber; Pernille Thorbek
2017-01-01
Protection of ecosystem services is increasingly emphasized as a risk-assessment goal, but there are wide gaps between current ecological risk-assessment endpoints and potential effects on services provided by ecosystems. The authors present a framework that links common ecotoxicological endpoints to chemical impacts on populations and communities and the ecosystem...
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Moschino, V; Schintu, M; Marrucci, A; Marras, B; Nesto, N; Da Ros, L
2017-09-15
In the Marine Protected Area of La Maddalena Archipelago, environmental protection rules and safeguard measures for nautical activities have helped in reducing anthropogenic pressure; however, tourism related activities remain particularly significant in summer. With the aim of evaluating their impacts, the biomarker approach using transplanted Mytilus galloprovincialis as sentinel organisms coupled with POCIS deployment was applied. Mussels, translocated to four marine areas differently impacted by tourism activities, were sampled before, during and after the tourist season. Moreover, endocrine disruptors in passive samplers POCIS and the cellular toxicity of whole POCIS extracts on mussel haemocytes were evaluated to integrate ecotoxicological information. Lysosomal biomarkers, condition index and mortality rate, as well as metals in tissues suggested an alteration of the health status of mussels transplanted to the most impacted sites. The cellular toxicity of POCIS extracts was pointed out, notwithstanding the concentrations of the examined compounds were always below the detection limits. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Macken, Ailbhe; Giltrap, Michelle; Foley, Barry; McGovern, Evin; McHugh, Brendan; Davoren, Maria
2008-06-01
This paper describes the ecotoxicological evaluation of five organic contaminants frequently detected in marine sediments (tributyltin, triphenyltin, benzo[a]pyrene, fluoranthene, and PCB 153) using three marine species (Vibrio fischeri, Tetraselmis suecica, and Tisbe battagliai). The sensitivity of each species varied for all compounds. The triorganotins were consistently the most toxic to all species. The applicability of each test system to assess the acute toxicity of environmental contaminants and their use in Toxicity Identification Evaluation (TIE) is discussed. Suitability of the Microtox and T. battagliai tests for employment in TIE studies were further assessed through spiking experiments with tributyltin. Results demonstrated that the most effective treatment to remove organotin toxicity from the sample was the C18 resin. The results of this study have important implications for risk assessment in estuarine and coastal waters in Ireland, where, at present the monitoring of sediment and water quality is predominantly reliant on chemical analysis alone.
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Domene, Xavier; Alcañiz, Josep M; Andrés, Pilar
2008-02-01
Development of methodologies to assess the safety of reusing polluted organic wastes in soil is a priority in Europe. In this study, and coupled with chemical analysis, seven organic wastes were subjected to different aquatic and soil bioassays. Tests were carried out with solid-phase waste and three different waste eluates (water, methanol, and dichloromethane). Solid-phase assays were indicated as the most suitable for waste testing not only in terms of relevance for real situations, but also because toxicity in eluates was generally not representative of the chronic effects in solid-phase. No general correlations were found between toxicity and waste pollutant burden, neither in solid-phase nor in eluate assays, showing the inability of chemical methods to predict the ecotoxicological risks of wastes. On the contrary, several physicochemical parameters reflecting the degree of low organic matter stability in wastes were the main contributors to the acute toxicity seen in collembolans and daphnids.
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Ecotoxicology and spatial modeling in population dynamics: an illustration with brown trout.
Chaumot, Arnaud; Charles, Sandrine; Flammarion, Patrick; Auger, Pierre
2003-05-01
We developed a multiregion matrix population model to explore how the demography of a hypothetical brown trout population living in a river network varies in response to different spatial scenarios of cadmium contamination. Age structure, spatial distribution, and demographic and migration processes are taken into account in the model. Chronic or acute cadmium concentrations affect the demographic parameters at the scale of the river range. The outputs of the model constitute population-level end points (the asymptotic population growth rate, the stable age structure, and the asymptotic spatial distribution) that allow comparing the different spatial scenarios of contamination regarding the demographic response at the scale of the whole river network. An analysis of the sensitivity of these end points to lower order parameters enables us to link the local effects of cadmium to the global demographic behavior of the brown trout population. Such a link is of broad interest in the point of view of ecotoxicological management.
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Ismail, Ahmad; Yusof, Shahrizad
2011-01-01
Several organisms have been used as indicators, bio-monitoring agents or test organisms in ecotoxicological studies. A close relative of the well established Japanese medaka, the Java medaka (Oryzias javanicus), has the potential to be a test organism. The fish is native to the estuaries of the Malaysian Peninsula, Thailand, Indonesia and Singapore. In this study, newly fertilised eggs were exposed to different concentrations of Cd and Hg. Observations were done on the development of the embryos. Exposure to low levels of Cd and Hg (0.01-0.05 ppm) resulted in several developmental disorders that led to death. Exposure to ≥1.0 ppm Cd resulted in immediate developmental arrest. The embryos of Java medaka showed tolerance to a certain extent when exposed to ≥1.0 ppm Hg compared to Cd. Based on the sensitivity of the embryos, Java medaka is a suitable test organism for ecotoxicology in the tropical region. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Ecotoxicological and genotoxic assessment of hospital laundry wastewaters.
Kern, Deivid Ismael; Schwaickhardt, Rômulo de Oliveira; Lutterbeck, Carlos Alexandre; Kist, Lourdes Teresinha; Alcayaga, Eduardo Alexis Lobo; Machado, Ênio Leandro
2015-01-01
The aim of the present study was to assess the ecotoxicity and genotoxicity of hospital laundry wastewaters generated from a regional hospital located in Rio Pardo Valley in the state of Rio Grande do Sul, Brazil. Physicochemical, microbiological, ecotoxicological, and genotoxic analyses were performed, and the results indicate that some parameters were not in accordance with the limit concentrations established by Brazilian and international guidelines for urban wastewaters. Daphnia magna (EC50 2.01%) and Danio rerio (LC50 29.25%) acute toxicity was detected, and sublethal effects were identified in Lactuca sativa (IC25 12.50%) and Allium cepa (IC25 51.25%). Cytotoxicity was observed at the five wastewater concentrations used yielding statistically significant differences (p < 0.05) in the meristematic cells of A. cepa compared with the negative control. The results obtained here warn about the necessity to develop treatment methods that can mitigate the environmental impacts caused by the ecotoxicity and genotoxicity of hospital laundry wastewaters.
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Pretti, Carlo; Oliva, Matteo; Mennillo, Elvira; Barbaglia, Martina; Funel, Marco; Reddy Yasani, Bhaskar; Martinelli, Elisa; Galli, Giancarlo
2013-12-01
Novel films were prepared by condensation curing reaction of a poly(dimethyl siloxane) (PDMS) matrix with bismuth neodecanoate and dibutyltin diacetate catalysts. An ecotoxicological study was performed on the leachates of the coatings using the bacterium Vibrio fischeri, the unicellular alga Dunaliella tertiolecta, the crustacean Artemia salina and the fish Sparus aurata (larvae) as testing organisms. A copper-based self-polishing commercial paint was also tested as reference. The results showed that the tin-catalysed coatings and the copper paint were highly toxic against at least two of the four test organisms, whereas bismuth-catalysed coatings did not show any toxic effect. Moreover, the same biological assessment was also carried out on PDMS coatings containing a surface-active fluorinated polymer. The toxicity of the entire polymeric system resulted only from the tin catalyst used for the condensation curing reaction, as the bismuth catalysed coatings incorporating the surface-active polymer remained atoxic toward all the tested organisms. © 2013 Elsevier Inc. All rights reserved.
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Ecotoxicological characterization of hazardous wastes.
Wilke, B-M; Riepert, F; Koch, Christine; Kühne, T
2008-06-01
In Europe hazardous wastes are classified by 14 criteria including ecotoxicity (H 14). Standardized methods originally developed for chemical and soil testing were adapted for the ecotoxicological characterization of wastes including leachate and solid phase tests. A consensus on which tests should be recommended as mandatory is still missing. Up to now, only a guidance on how to proceed with the preparation of waste materials has been standardized by CEN as EN 14735. In this study, tests including higher plants, earthworms, collembolans, microorganisms, duckweed and luminescent bacteria were selected to characterize the ecotoxicological potential of a boiler slag, a dried sewage sludge, a thin sludge and a waste petrol. In general, the instructions given in EN 14735 were suitable for all wastes used. The evaluation of the different test systems by determining the LC/EC(50) or NOEC-values revealed that the collembolan reproduction and the duckweed frond numbers were the most sensitive endpoints. For a final classification and ranking of wastes the Toxicity Classification System (TCS) using EC/LC(50) values seems to be appropriate.
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Miranda, Lorena S; Moreira, Ícaro T A; Oliveira, Olívia M C; Santos, Carlito P; Pinheiro, Samires M M; Oliveira, Lua M L; Martins, Adriele B O; Filho, Milton S C
2016-11-15
Recent studies have revealed the occurrence of a natural process of interaction between oil droplets and suspended particulate material, resulting in the formation of aggregates which are dispersed in the water column, known as oil-suspended particulate material aggregates (OSAs). The experiments aimed to investigate the contribution of OSAS in indicating where most likely is the oil sedimentation in the São Paulo river, Todos os Santos Bay, Brazil, in order to predict possible ecotoxicological risks caused by oil spills. The results showed that salinity and MPS concentration interfere on the formation of aggregates. In addition, the point 3 was nominated as the most vulnerable area to the potential ecotoxicological impacts of oil spills and should be treated as a priority area for the application of preventive and mitigating techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.
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[Ecotoxicological study of chlorinated pesticides].
Rosival, L; Szokolay, A; Uhnák, J
1980-01-01
The authors describe a model for the ecotoxicological investigation of pesticide residues guided by the analysis of various links of the food chain and of human materials. It is pointed to the possibility of studying the dynamics of the exposure to human beings by analyzing gynaecological material (prenatal stage) and samples obtained at necropsy from human beings of varying age (different durations of exposure). The observations of the relative accumulation of hexachlorobenzene, beta-BHC and DDT in butter, human milk and human fat in a region with intensive cultivation revealed a considerble accumulation of hexachlorobenzene which reaches the level of DDT. The conclusion drawn from ecotoxicological studies indicates that a reduction of the tolerances of pesticide residues in raw materials for baby foods is imperative. The analyses of gynaecological material (202 samples of the available content of the uterus and 24 placental and embryonic specimens) permitted to evidence a significant difference between two regions and a specific relationship of the observed substances and their metabolites to the fat-dissolving power of the analyzed materials.
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Ephyra jellyfish as a new model for ecotoxicological bioassays.
Faimali, M; Garaventa, F; Piazza, V; Costa, E; Greco, G; Mazzola, V; Beltrandi, M; Bongiovanni, E; Lavorano, S; Gnone, G
2014-02-01
The aim of this study was a preliminary investigation on the possibility of using the ephyra of Scyphozoan jellyfish Aurelia aurita (Linnaeus, 1758), the common moon jellyfish, as an innovative model organism in marine ecotoxicology. A series of sequential experiments have been carried out in laboratory in order to investigate the influence of different culturing and methodological parameters (temperature, photoperiod, ephyrae density and age) on behavioural end-points (% of Frequency of Pulsations) and standardize a testing protocol. After that, the organisms have been exposed to two well known reference toxic compounds (Cadmium Nitrate and SDS) in order to analyse the acute and behavioural responses during static exposure. Results of this work indicate that the proposed behavioural end-point, frequency of pulsations (Fp), is an easily measurable one and can be used coupled with an acute one (immobilization) and that ephyrae of jellyfish are very promising model organisms for ecotoxicological investigation. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Morgana, Silvia; Gambardella, Chiara; Falugi, Carla; Pronzato, Roberto; Garaventa, Francesca; Faimali, Marco
2016-04-01
Behavioral endpoints have been used for decades to assess chemical impacts at concentrations unlikely to cause mortality. With recently developed techniques, it is possible to investigate the swimming behavior of several organisms under laboratory conditions. The aims of this study were: i) assessing for the first time the feasibility of swimming speed analysis of the early developmental stage sea urchin Paracentrotus lividus by an automatic recording system ii) investigating any Swimming Speed Alteration (SSA) on P. lividus early stages exposed to a chemical reference; iii) identifying the most suitable stage for SSA test. Results show that the swimming speed of all the developmental stages was easily recorded. The swimming speed was inhibited as a function of toxicant concentration. Pluteus were the most appropriate stage for evaluating SSA in P. lividus as ecotoxicological endpoint. Finally, swimming of sea urchin early stages represents a sensitive endpoint to be considered in ecotoxicological investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Ferris, D Lance; Reb, Jochen; Lian, Huiwen; Sim, Samantha; Ang, Dionysius
2018-03-01
Past research on dynamic workplace performance evaluation has taken as axiomatic that temporal performance trends produce naïve extrapolation effects on performance ratings. That is, we naïvely assume that an individual whose performance has trended upward over time will continue to improve, and rate that individual more positively than an individual whose performance has trended downward over time-even if, on average, the 2 individuals have performed at an equivalent level. However, we argue that such naïve extrapolation effects are more pronounced in Western countries than Eastern countries, owing to Eastern countries having a more holistic cognitive style. To test our hypotheses, we examined the effect of performance trend on expectations of future performance and ratings of past performance across 2 studies: Study 1 compares the magnitude of naïve extrapolation effects among Singaporeans primed with either a more or less holistic cognitive style, and Study 2 examines holistic cognitive style as a mediating mechanism accounting for differences in the magnitude of naïve extrapolation effects between American and Chinese raters. Across both studies, we found support for our predictions that dynamic performance trends have less impact on the ratings of more holistic thinkers. Implications for the dynamic performance and naïve extrapolation literatures are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
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Terrestrial Eco-Toxicological Tests as Screening Tool to Assess Soil Contamination in Krompachy Area
NASA Astrophysics Data System (ADS)
Ol'ga, Šestinová; Findoráková, Lenka; Hančuľák, Jozef; Fedorová, Erika; Tomislav, Špaldon
2016-10-01
In this study, we present screening tool of heavy metal inputs to agricultural and permanent grass vegetation of the soils in Krompachy. This study is devoted to Ecotoxicity tests, Terrestrial Plant Test (modification of OECD 208, Phytotoxkit microbiotest on Sinapis Alba) and chronic tests of Earthworm (Dendrobaena veneta, modification of OECD Guidelines for the testing of chemicals 317, Bioaccumulation in Terrestrial Oligochaetes) as practical and sensitive screening method for assessing the effects of heavy metals in Krompachy soils. The total Cu, Zn, As, Pb and Hg concentrations and eco-toxicological tests of soils from the Krompachy area were determined of 4 sampling sites in 2015. An influence of the sampling sites distance from the copper smeltery on the absolutely concentrations of metals were recorded for copper, lead, zinc, arsenic and mercury. The highest concentrations of these metals were detected on the sampling sites up to 3 km from the copper smeltery. The samples of soil were used to assess of phytotoxic effect. Total mortality was established at earthworms using chronic toxicity test after 7 exposure days. The results of our study confirmed that no mortality was observed in any of the study soils. Based on the phytotoxicity testing, phytotoxic effects of the metals contaminated soils from the samples 3KR (7-9) S.alba seeds was observed.
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Acute toxicity tests and meta-analysis identify gaps in tropical ecotoxicology for amphibians.
Ghose, Sonia L; Donnelly, Maureen A; Kerby, Jacob; Whitfield, Steven M
2014-09-01
Amphibian populations are declining worldwide, particularly in tropical regions where amphibian diversity is highest. Pollutants, including agricultural pesticides, have been identified as a potential contributor to decline, yet toxicological studies of tropical amphibians are very rare. The present study assesses toxic effects on amphibians of 10 commonly used commercial pesticides in tropical agriculture using 2 approaches. First, the authors conducted 8-d toxicity assays with formulations of each pesticide using individually reared red-eyed tree frog (Agalychnis callidryas) tadpoles. Second, they conducted a review of available data for the lethal concentration to kill 50% of test animals from the US Environmental Protection Agency's ECOTOX database to allow comparison with their findings. Lethal concentration estimates from the assays ranged over several orders of magnitude. The nematicides terbufos and ethoprophos and the fungicide chlorothalonil were very highly toxic, with evident effects within an order of magnitude of environmental concentrations. Acute toxicity assays and meta-analysis show that nematicides and fungicides are generally more toxic than herbicides yet receive far less research attention than less toxic herbicides. Given that the tropics have a high diversity of amphibians, the findings emphasize the need for research into the effects of commonly used pesticides in tropical countries and should help guide future ecotoxicological research in tropical regions. © 2014 SETAC.
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Feeding Behavior of an Aquatic Snail as a Simple Endpoint to Assess the Exposure to Cadmium.
Alonso, Álvaro; Valle-Torres, Guillermo
2018-01-01
One of the aims of ecotoxicology is the assessment of the effects of chemicals on the ecosystems. Bioassays assessing lethality are frequently used in ecotoxicology, however they usually employ supra-environmental toxic concentrations. Toxicity tests employing behavioral endpoints may present a balance between simplicity (i.e., laboratory bioassays) and complexity (i.e., relevant ecological effects). The aim of this study was to develop a feeding behavioral bioassay with the aquatic snail, Potamopyrgus antipodarum, which included a 2 days exposure to cadmium, followed by a 9 days post-exposure observational period. Several behavioral feeding endpoints were monitored, including percentage of actively feeding animals, percentage of animals in food quadrants and a mobility index. The percentage of actively feeding animals was reduced by the four cadmium treatments (0.009, 0.026, 0.091 and 0.230 mg Cd/L) with the stronger effect in the highest concentration. The two highest cadmium concentrations significantly reduced the percentage of animals in food quadrants and the mobility index. Therefore, the percentage of actively feeding animals was the most sensitive endpoint to cadmium toxicity as the four cadmium concentrations caused a significant decrease in this endpoint. It is concluded that feeding behavior is a useful endpoint to detect the exposure of aquatic snails to cadmium.
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Acute and chronic toxicity of six anticancer drugs on rotifers and crustaceans.
Parrella, Alfredo; Lavorgna, Margherita; Criscuolo, Emma; Russo, Chiara; Fiumano, Vittorio; Isidori, Marina
2014-11-01
The growing use of cytostatic drugs is gaining relevance as an environmental concern. Environmental and distribution studies are increasing due to the development of accurate analytical methods, whereas ecotoxicological studies are still lacking. The aim of the present study was to investigate the acute and chronic toxicity of six cytostatics (5-fluorouracil, capecitabine, cisplatin, doxorubicin, etoposide, and imatinib) belonging to five classes of Anatomical Therapeutic Classification (ATC) on primary consumers of the aquatic chain (Daphnia magna, Ceriodaphnia dubia, Brachionus calyciflorus, and Thamnocephalus platyurus). Acute ecotoxicological effects occurred at concentrations in the order of mgL(-)(1), higher than those predicted in the environment, and the most acutely toxic drugs among those tested were cisplatin and doxorubicin for most aquatic organisms. For chronic toxicity, cisplatin and 5-fluorouracil showed the highest toxic potential in all test organisms, inducing 50% reproduction inhibition in crustaceans at concentrations on the order of μgL(-)(1). Rotifers were less susceptible to these pharmaceuticals. On the basis of chronic results, the low effective concentrations suggest a potential environmental risk of cytostatics. Thus, this study could be an important starting point for establishing the real environmental impact of these substances. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Khudur, Leadin Salah; Shahsavari, Esmaeil; Miranda, Ana F; Morrison, Paul D; Nugegoda, Dayanthi; Ball, Andrew S
2015-10-01
Diesel represents a common environmental contaminant as a result of operation, storage, and transportation accidents. The bioremediation of diesel in a contaminated soil is seen as an environmentally safe approach to treat contaminated land. The effectiveness of the remediation process is usually assessed by the degradation of the total petroleum hydrocarbon (TPH) concentration, without considering ecotoxicological effects. The aim of this study was to assess the efficacy of two bioremediation strategies in terms of reduction in TPH concentration together with ecotoxicity indices and changes in the bacterial diversity assessed using PCR-denaturing gradient gel electrophoresis (DGGE). The biostimulation strategy resulted in a 90 % reduction in the TPH concentration versus 78 % reduction from the natural attenuation strategy over 12 weeks incubation in a laboratory mesocosm-containing diesel-contaminated soil. In contrast, the reduction in the ecotoxicity resulting from the natural attenuation treatment using the Microtox and earthworm toxicity assays was more than double the reduction resulting from the biostimulation treatment (45 and 20 % reduction, respectively). The biostimulated treatment involved the addition of nitrogen and phosphorus in order to stimulate the microorganisms by creating an optimal C:N:P molar ratio. An increased concentration of ammonium and phosphate was detected in the biostimulated soil compared with the naturally attenuated samples before and after the remediation process. Furthermore, through PCR-DGGE, significant changes in the bacterial community were observed as a consequence of adding the nutrients together with the diesel (biostimulation), resulting in the formation of distinctly different bacterial communities in the soil subjected to the two strategies used in this study. These findings indicate the suitability of both bioremediation approaches in treating hydrocarbon-contaminated soil, particularly biostimulation. Although biostimulation represents a commercially viable bioremediation technology for use in diesel-contaminated soils, further research is required to determine the ecotoxicological impacts of the intervention.
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Pivato, Alberto; Vanin, Stefano; Raga, Roberto; Lavagnolo, Maria Cristina; Barausse, Alberto; Rieple, Antonia; Laurent, Alexis; Cossu, Raffaello
2016-03-01
Over the last decade, the number of decentralized farm biogas plants has increased significantly in the EU. This development leads not only to an increasing amount of biogas produced, but also to a higher amount of digestate obtained. One of the most attractive options to manage the digestate is to apply it as biofertiliser to the soil, because this gives the opportunity of recovering the nutrients, primarily nitrogen and phosphorus, and of attenuating the loss of organic matter suffered by soils under agricultural exploitation. Studies have claimed that digestates can present a residual biodegradability, and contain complex organic elements, salts or pathogenic bacteria that can damage terrestrial organisms. However few ecotoxicological studies have been performed to evaluate the ecological impact of digestate application on soil. In this study, the use of digestate as biofertiliser in agriculture was assessed by a battery of ecotoxicological tests considering the potential pollutants present in the digestate as a whole by using the "matrix-based" approach (also known as "whole effluent toxicity" for eluates or wastewater effluents). The direct and indirect tests included plant bioassays with Lepidium sativum, earthworm bioassays with Eisenia fetida, aquatic organisms (Artemia sp. and Daphnia magna) and luminescent bacteria bioassays (Vibrio fischeri). Direct tests occurred to be more sensitive than indirect tests. The earthworm bioassays did not show serious negative effects for concentrations up to 15% (dry weight/dry weight percent, w/w dm) and the plant bioassays showed no negative effect, but rather a positive one for concentrations lower than 20% (w/w dm), which encourages the use of digestate as a biofertiliser in agriculture provided that proper concentrations are used. The indirect tests, on the eluate, with the using aquatic organisms and luminescent bacteria showed an LC50 value of 13.61% volume/volume percent, v/v) for D. magna and no toxicity for Artemia sp. and V. fischeri. The ecotoxicological parameters obtained from the experimental activity have been analyzed so that they could serve in both ecological risk assessment (ERA) and life cycle assessment (LCA) to assess the risks and impacts of using digestate as a biofertiliser in agriculture. An interim effect factor of 1.17E-3m(3)/kg-in-soil is advocated and can be used in life cycle impact assessment modelling of terrestrial ecotoxicity. A predicted non effect concentration for soil organisms was defined at 341 mg-digestate/kg-soil and can be used for the dose-response assessment step in ERA. Although these values are recommended for use in ERA and LCA applications, it should be stressed that they underlie important uncertainties, which should be reduced by increasing the number of toxicological tests, in particular of chronic studies conducted at different trophic levels. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Phulpoto, Anwar Hussain; Qazi, Muneer Ahmed; Haq, Ihsan Ul; Phul, Abdul Rahman; Ahmed, Safia; Kanhar, Nisar Ahmed
2018-06-01
The present study validates the oil-based paint bioremediation potential of Bacillus subtilis NAP1 for ecotoxicological assessment using a three-dimensional multi-species bio-testing model. The model included bioassays to determine phytotoxic effect, cytotoxic effect, and antimicrobial effect of oil-based paint. Additionally, the antioxidant activity of pre- and post-bioremediation samples was also detected to confirm its detoxification. Although, the pre-bioremediation samples of oil-based paint displayed significant toxicity against all the life forms. However, post-bioremediation, the cytotoxic effect against Artemia salina revealed substantial detoxification of oil-based paint with LD 50 of 121 μl ml -1 (without glucose) and > 400 μl ml -1 (with glucose). Similarly, the reduction in toxicity against Raphanus raphanistrum seeds germination (%FG = 98 to 100%) was also evident of successful detoxification under experimental conditions. Moreover, the toxicity against test bacterial strains and fungal strains was completely removed after bioremediation. In addition, the post-bioremediation samples showed reduced antioxidant activities (% scavenging = 23.5 ± 0.35 and 28.9 ± 2.7) without and with glucose, respectively. Convincingly, the present multi-species bio-testing model in addition to antioxidant studies could be suggested as a validation tool for bioremediation experiments, especially for middle and low-income countries. Graphical abstract ᅟ.
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Fabbrocini, Adele; D'Adamo, Raffaele; Del Prete, Francesco; Langellotti, Antonio Luca; Rinna, Francesca; Silvestri, Fausto; Sorrenti, Gerarda; Vitiello, Valentina; Sansone, Giovanni
2012-10-01
The aim of this study was to evaluate the feasibility of using cryopreserved S. aurata semen in spermiotoxicity tests. Cryopreservation is a biotechnology that can provide viable gametes and embryos on demand, rather than only in the spawning season, thus overcoming a limitation that has hindered the use of some species in ecotoxicological bioassays. Firstly, the sperm motility pattern of cryopreserved semen was evaluated after thawing by means of both visual and computer-assisted analyses. Motility parameters in the cryopreserved semen did not change significantly in the first hour after thawing, meaning that they were maintained for long enough to enable their use in spermiotoxicity tests. In the second phase of the research, bioassays were performed, using cadmium as the reference toxicant, in order to evaluate the sensitivity of cryopreserved S. aurata semen to ecotoxicological contamination. The sensitivity of the sperm motility parameters used as endpoints (motility percentages and velocities) proved to be comparable to what has been recorded for the fresh semen of other aquatic species (LOECs from 0.02 to 0.03 mg L(-1)). The test showed good reliability and was found to be rapid and easy to perform, requiring only a small volume of the sample. Moreover, cryopreserved semen is easy to store and transfer and makes it possible to perform bioassays in different sites or at different times with the same batch of semen. The proposed bioassay is therefore a promising starting point for the development of toxicity tests that are increasingly tailored to the needs of ecotoxicology and environmental quality evaluation strategies. Copyright © 2012 Elsevier Inc. All rights reserved.
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Using models to extrapolate population-level effects from laboratory toxicity tests in support of population risk assessments. Munns, W.R., Jr.*, Anne Kuhn, Matt G. Mitro, and Timothy R. Gleason, U.S. EPA ORD NHEERL, Narragansett, RI, USA. Driven in large part by management goa...
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Toxicogenomics in Environmental Science.
Brinke, Alexandra; Buchinger, Sebastian
This chapter reviews the current knowledge and recent progress in the field of environmental, aquatic ecotoxicogenomics with a focus on transcriptomic methods. In ecotoxicogenomics the omics technologies are applied for the detection and assessment of adverse effects in the environment, and thus are to be distinguished from omics used in human toxicology [Snape et al., Aquat Toxicol 67:143-154, 2004]. Transcriptomic methods in ecotoxicology are applied to gain a mechanistic understanding of toxic effects on organisms or populations, and thus aim to bridge the gap between cause and effect. A worthwhile effect-based interpretation of stressor induced changes on the transcriptome is based on the principle of phenotypic-anchoring [Paules, Environ Health Perspect 111:A338-A339, 2003]. Thereby, changes on the transcriptomic level can only be identified as effects if they are clearly linked to a specific stressor-induced effect on the macroscopic level. By integrating those macroscopic and transcriptomic effects, conclusions on the effect-inducing type of the stressor can be drawn. Stressor-specific effects on the transcriptomic level can be identified as stressor-specific induced pathways, transcriptomic patterns, or stressors-specific genetic biomarkers. In this chapter, examples of the combined application of macroscopic and transcriptional effects for the identification of environmental stressors, such as aquatic pollutants, are given and discussed. By means of these examples, challenges on the way to a standardized application of transcriptomics in ecotoxicology are discussed. This is also done against the background of the application of transcriptomic methods in environmental regulation such as the EU regulation Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).
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Brami, C; Glover, A R; Butt, K R; Lowe, C N
2017-05-01
Soil dwelling earthworms are now adopted more widely in ecotoxicology, so it is vital to establish if standardised test parameters remain applicable. The main aim of this study was to determine the influence of OECD artificial soil on selected soil-dwelling, endogeic earthworm species. In an initial experiment, biomass change in mature Allolobophora chlorotica was recorded in Standard OECD Artificial Soil (AS) and also in Kettering Loam (KL). In a second experiment, avoidance behaviour was recorded in a linear gradient with varying proportions of AS and KL (100% AS, 75% AS + 25% KL, 50% KS + 50% KL, 25% AS + 75% KL, 100% KL) with either A. chlorotica or Octolasion cyaneum. Results showed a significant decrease in A. chlorotica biomass in AS relative to KL, and in the linear gradient, both earthworm species preferentially occupied sections containing higher proportions of KL over AS. Soil texture and specifically % composition and particle size of sand are proposed as key factors that influenced observed results. This research suggests that more suitable substrates are required for ecotoxicology tests with soil dwelling earthworms.
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Durán, I; Beiras, R
2013-10-01
Acute water quality criteria (WQC) for the protection of coastal ecosystems are developed on the basis of short-term ecotoxicological data using the most sensitive life stages of representative species from the main taxa of marine water column organisms. A probabilistic approach based on species sensitivity distribution (SSD) curves has been chosen and compared to the WQC obtained applying an assessment factor to the critical toxicity values, i.e. the 'deterministic' approach. The criteria obtained from HC5 values (5th percentile of the SSD) were 1.01 μg/l for Hg, 1.39 μg/l for Cu, 3.83 μg/l for Cd, 25.3 μg/l for Pb and 8.24 μg/l for Zn. Using sensitive early life stages and very sensitive endpoints allowed calculation of WQC for marine coastal ecosystems. These probabilistic WQC, intended to protect 95% of the species in 95% of the cases, were calculated on the basis of a limited ecotoxicological dataset, avoiding the use of large and uncertain assessment factors. Copyright © 2013 Elsevier B.V. All rights reserved.
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Environmental legislation and aquatic ecotoxicology in Mexico: past, present and future scenarios.
Mendoza-Cantú, Ania; Ramírez-Romero, Patricia; Pica-Granados, Yolanda
2007-08-01
The consolidation of environmental legislation is fundamental for governments that wish to support and promote different actions focused on reducing pollution and protecting natural water resources in order to maintain the present and future benefits that water provides for human beings and wild life. Environmental laws are essential for sustaining human activities and health, preserving biodiversity and promoting sustainable development. In this context, it is important that environmental regulations concentrate on preventing or reducing the harmful impact of pollutants on organisms and ecosystems. The introduction of toxicity bioassays in environmental regulations is a positive step toward achieving this goal. In Mexico, the development of environmental legislation and the introduction of bioassays in water regulation are part of a very recent and complex journey. This article describes how aquatic ecotoxicology tools, particularly bioassays, have influenced water pollution policies in Mexico. Three scenarios are reviewed: the background of Mexican legislation on water protection and Mexico's participation in the Watertox project; the actual efforts of SEMARNAT to develop bioassay batteries for this country; and, the challenges and perspectives of ecotoxicological bioassays as regulatory instruments.
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A. Dennis Lemly
1997-01-01
This paper describes a method for deriving site-specific water quality criteria for selenium using a two-step process: (1) gather information on selenium residues and biological effects at the site and in down-gradient systems and (2) examine criteria based on the degree of bioaccumulation, the relationship between mea-sured residues and threshold concentrations for...
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Dagnino, Alessandro; Bo, Tiziano; Copetta, Andrea; Fenoglio, Stefano; Oliveri, Caterina; Bencivenga, Mauro; Felli, Angelo; Viarengo, Aldo
2013-10-01
With the aim of supporting decision makers to manage contamination in freshwater environments, an innovative expert decision support system (EDSS) was developed. The EDSS was applied in a sediment quality assessment along the Bormida river (NW, Italy) which has been heavily contaminated by an upstream industrial site for more than a century. Sampling sites were classified by means of comparing chemical concentrations with effect-based target values (threshold and probable effect concentrations). The level of each contaminant and the combined toxic pressure were used to rank sites into three categories: (i) uncontaminated (8 sites), (ii) mildly contaminated (4) and (iii) heavily contaminated (19). In heavily contaminated sediments, an environmental risk index (EnvRI) was determined by means of integrating chemical data with ecotoxicological and ecological parameters (triad approach). In addition a sediment risk index (SedRI) was computed from combining chemical and ecotoxicological data. Eight sites exhibited EnvRI values ≥0.25, the safety threshold level (range of EnvRI values: 0.14-0.31) whereas SedRI exceeded the safety threshold level at 6 sites (range of SedRI values: 0.16-0.36). At sites classified as mildly contaminated, sublethal biomarkers were integrated with chemical data into a biological vulnerability index (BVI), which exceeded the safety threshold level at one site (BVI value: 0.28). Finally, potential human risk was assessed in selected stations (11 sites) by integrating genotoxicity biomarkers (GTI index falling in the range 0.00-0.53). General conclusions drawn from the EDSS data include: (i) in sites classified as heavily contaminated, only a few exhibited some significant, yet limited, effects on biodiversity; (ii) restrictions in re-using sediments from heavily contaminated sites found little support in ecotoxicological data; (iii) in the majority of the sites classified as mildly contaminated, tested organisms exhibited low response levels; (iv) preliminary results on genotoxicity biomarkers indicate possible negative consequences for humans if exposed to river sediments from target areas. © 2013.
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Paule, A; Roubeix, V; Swerhone, G D W; Roy, J; Lauga, B; Duran, R; Delmas, F; Paul, E; Rols, J L; Lawrence, J R
2016-03-01
Residual pesticides applied to crops migrate from agricultural lands to surface and ground waters. River biofilms are the first aquatic non-target organisms which interact with pesticides. Therefore, ecotoxicological experiments were performed at laboratory scale under controlled conditions to investigate the community-level responses of river biofilms to a chloroacetanilide herbicide (alachlor) and organic solvent (methanol) exposure through the development referenced to control. Triplicate rotating annular bioreactors, inoculated with river water, were used to cultivate river biofilms under the influence of 1 and 10 μg L(-1) of alachlor and 25 mg L(-1) of methanol. For this purpose, functional (thymidine incorporation and carbon utilization spectra) and structural responses of microbial communities were assessed after 5 weeks of development. Structural aspects included biomass (chlorophyll a, confocal laser scanning microscopy) and composition (fluor-conjugated lectin binding, molecular fingerprinting, and diatom species composition). The addition of alachlor resulted in a significant reduction of bacterial biomass at 1 μg L(-1), whereas at 10 μg L(-1), it induced a significant reduction of exopolymer lectin binding, algal, bacterial, and cyanobacterial biomass. However, there were no changes in biofilm thickness or thymidine incorporation. No significant difference between the bacterial community structures of control and alachlor-treated biofilms was revealed by terminal restriction fragment length polymorphism (T-RFLP) analyses. However, the methanol-treated bacterial communities appeared different from control and alachlor-treated communities. Moreover, methanol treatment resulted in an increase of bacterial biomass and thymidine incorporation as well. Changes in dominant lectin binding suggested changes in the exopolymeric substances and community composition. Chlorophyll a and cyanobacterial biomass were also altered by methanol. This study suggested that the concentration-dependent effect of alachlor mainly remains limited to biomass and growth inhibition without apparent changes of structural and functional characteristics measured. Our work also establishes the potential toxic effects of organic solvents on river biofilm in ecotoxicological experiments. For the ecotoxicological experiments, the alternative of dissolution in organic solvent followed by its evaporation, depositing the chemical on a glass surface prior to dissolution in river water used here, appears to allow exposure while minimizing the effect of organic solvent.
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Cosmogony as an extrapolation of magnetospheric research
NASA Technical Reports Server (NTRS)
Alfven, H.
1984-01-01
A theory of the origin and evolution of the Solar System which considered electromagnetic forces and plasma effects is revised in light of information supplied by space research. In situ measurements in the magnetospheres and solar wind can be extrapolated outwards in space, to interstellar clouds, and backwards in time, to the formation of the solar system. The first extrapolation leads to a revision of cloud properties essential for the early phases in the formation of stars and solar nebulae. The latter extrapolation facilitates analysis of the cosmogonic processes by extrapolation of magnetospheric phenomena. Pioneer-Voyager observations of the Saturnian rings indicate that essential parts of their structure are fossils from cosmogonic times. By using detailed information from these space missions, it is possible to reconstruct events 4 to 5 billion years ago with an accuracy of a few percent.
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Measurement accuracies in band-limited extrapolation
NASA Technical Reports Server (NTRS)
Kritikos, H. N.
1982-01-01
The problem of numerical instability associated with extrapolation algorithms is addressed. An attempt is made to estimate the bounds for the acceptable errors and to place a ceiling on the measurement accuracy and computational accuracy needed for the extrapolation. It is shown that in band limited (or visible angle limited) extrapolation the larger effective aperture L' that can be realized from a finite aperture L by over sampling is a function of the accuracy of measurements. It is shown that for sampling in the interval L/b absolute value of xL, b1 the signal must be known within an error e sub N given by e sub N squared approximately = 1/4(2kL') cubed (e/8b L/L')(2kL') where L is the physical aperture, L' is the extrapolated aperture, and k = 2pi lambda.
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Ecotoxicological evaluation of swine manure disposal on tropical soils in Brazil.
Segat, Julia Corá; Alves, Paulo Roger Lopes; Baretta, Dilmar; Cardoso, Elke Jurandy Bran Nogueira
2015-12-01
Swine production in Brazil results in a great volume of manure that normally is disposed of as agricultural fertilizer. However, this form of soil disposal, generally on small farms, causes the accumulation of large amounts of manure and this results in contaminated soil and water tables. To evaluate the effects of increasing concentrations of swine manure on earthworms, several ecotoxicological tests were performed using Eisenia andrei as test organism in different tropical soils, classified respectively as Ultisol, Oxisol, and Entisol, as well as Tropical Artificial Soil (TAS). The survival, reproduction and behavior of the earthworms were evaluated in experiments using a completely randomized design, with five replications. In the Ultisol, Oxisol and TAS the swine manure showed no lethality, but in the Entisol it caused earthworm mortality (LOEC=45 m(3)ha(-1)). In the Entisol, the waste reduced the reproductive rate and caused avoidance behavior in E. andrei (LOEC=30 m(3)ha(-1)) even in lower concentrations. The Entisol is extremely sandy, with low cation exchange capacity (CEC), and this may be the reason for the higher toxicity on soil fauna, with the soil not being able to hold large amounts of pollutants (e.g. toxic metals), but leaving them in bioavailable forms. These results should be a warning of the necessity to consider soil parameters (e.g. texture and CEC) when evaluating soil contamination by means of ecotoxicological assays, as there still are no standards for natural soils in tropical regions. E. andrei earthworms act as indicators for a soil to support disposal of swine manure without generating harm to agriculture and ecosystems. Copyright © 2015 Elsevier Inc. All rights reserved.
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de Melo Gurgel, Piatã; Navoni, Julio Alejandro; de Morais Ferreira, Douglisnilson; do Amaral, Viviane Souza
2016-12-01
Water pollution generated by industrial effluents discharge is a threat to the maintenance of aquatic ecosystems and human development. The Jundiai River estuarine, located in Northeast Brazil, receives an industrial pretreated effluent load from the city of Macaíba/RN/Brazil. The present study aimed to assess the water quality of this water reservoir through i) physicochemical characterization, ii) quantification of metal concentration and iii) by an ecotoxicological assessment carried out using Mysidopsis juniae and Pomacea lineata. The study was performed throughout the period comprising May to September 2014. Physicochemical variables such as chloride, total solids and electrical conductivity presented values in the waste discharge point, significantly different with those located out of the waste releasing point. Apart from that, metal concentration showed variable behavior throughout the monitored period. Levels of Al, Fe, Cu, Cd, Cr, Ni, Pb and Ag were over the considered guidelines. Both natural and anthropogenic sources seem to be involved in the resulting environmental scenario. A reduction in the fecundity rate (using Mysidopsis juniae) along with an increase in mortality rate (in both species) was observed ratifying the presence of toxic substances in this water reservoir. Moreover, a correlation analysis stated an association of the aforementioned toxicological effects with the delivery of industrial waste products. The ecotoxicological assessment performed highlighted the presence of toxic substance/s in water from the Jundiai River. Especially as a consequence of industrial activity, a fact that might threaten the bioma and, therefore, the human health of the population settled in the studied region. Copyright © 2016 Elsevier B.V. All rights reserved.
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Chelinho, Sónia; Moreira-Santos, Matilde; Silva, Cátia; Costa, Catarina; Viana, Paula; Viegas, Cristina A; Fialho, Arsénio M; Ribeiro, Rui; Sousa, José Paulo
2012-07-01
The present study evaluated the bioremediation efficacy of a cleanup tool for atrazine-contaminated soils (Pseudomonas sp. ADP plus citrate [P. ADP + CIT]) at a semifield scale, combining chemical and ecotoxicological information. Three experiments representing worst-case scenarios of atrazine contamination for soil, surface water (due to runoff), and groundwater (due to leaching) were performed in laboratory simulators (100 × 40 × 20 cm). For each experiment, three treatments were set up: bioremediated, nonbioremediated, and a control. In the first, the soil was sprayed with 10 times the recommended dose (RD) for corn of Atrazerba and with P. ADP + CIT at day 0 and a similar amount of P. ADP at day 2. The nonbioremediated treatment consisted of soil spraying with 10 times the RD of Atrazerba (day 0). After 7 d of treatment, samples of soil (and eluates), runoff, and leachate were collected for ecotoxicological tests with plants (Avena sativa and Brassica napus) and microalgae (Pseudokirchneriella subcapitata) species. In the nonbioremediated soils, atrazine was very toxic to both plants, with more pronounced effects on plant growth than on seed emergence. The bioremediation tool annulled atrazine toxicity to A. sativa (86 and 100% efficacy, respectively, for seed emergence and plant growth). For B. napus, results point to incomplete bioremediation. For the microalgae, eluate and runoff samples from the nonbioremediated soils were extremely toxic; a slight toxicity was registered for leachates. After only 7 d, the ecotoxicological risk for the aquatic compartments seemed to be diminished with the application of P. ADP + CIT. In aqueous samples obtained from the bioremediated soils, the microalgal growth was similar to the control for runoff samples and slightly lower than control (by 11%) for eluates. Copyright © 2012 SETAC.
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Rocha, Luciana S; Lopes, I; Lopes, Cláudia B; Henriques, Bruno; Soares, Amadeu M V M; Duarte, Armando C; Pereira, Eduarda
2014-01-01
In the present work, the efficiency of rice husk to remove Hg(II) from river waters spiked with realistic environmental concentrations of this metal (μg L(-1) range) was evaluated. The residual levels of Hg(II) obtained after the remediation process were compared with the guideline values for effluents discharges and water for human consumption, and the ecotoxicological effects using organisms of different trophic levels were assessed. The rice husk sorbent proved to be useful in decreasing Hg(II) contamination in river waters, by reducing the levels of Hg(II) to values of ca. 8.0 and 34 μg L(-1), for an Hg(II) initial concentration of 50 and 500 μg L(-1), respectively. The remediation process with rice husk biowaste was extremely efficient in river waters spiked with lower levels of Hg(II), being able to eliminate the toxicity to the exposed organisms algae Pseudokirchneriella subcapitata and rotifer Brachionus calyciflorus and ensure the total survival of Daphnia magna species. For concentrations of Hg(II) tenfold higher (500 μg L(-1)), the remediation process was not adequate in the detoxification process, still, the rice husk material was able to reduce considerably the toxicity to the bacteria Vibrio fischeri, algae P. subcapitata and rotifer B. calyciflorus, whose responses where fully inhibited during its exposure to the non-remediated river water. The use of a battery of bioassays with organisms from different trophic levels and whose sensitivity revealed to be different and dependent on the levels of Hg(II) contamination proved to be much more accurate in predicting the ecotoxicological hazard assessment of the detoxification process by means of rice husk biowaste.
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Kumpiene, Jurate; Bert, Valérie; Dimitriou, Ioannis; Eriksson, Jan; Friesl-Hanl, Wolfgang; Galazka, Rafal; Herzig, Rolf; Janssen, Jolien; Kidd, Petra; Mench, Michel; Müller, Ingo; Neu, Silke; Oustriere, Nadège; Puschenreiter, Markus; Renella, Giancarlo; Roumier, Pierre-Hervé; Siebielec, Grzegorz; Vangronsveld, Jaco; Manier, Nicolas
2014-10-15
During the past decades a number of field trials with gentle remediation options (GRO) have been established on trace element (TE) contaminated sites throughout Europe. Each research group selects different methods to assess the remediation success making it difficult to compare efficacy between various sites and treatments. This study aimed at selecting a minimum risk assessment battery combining chemical and ecotoxicological assays for assessing and comparing the effectiveness of GRO implemented in seven European case studies. Two test batteries were pre-selected; a chemical one for quantifying TE exposure in untreated soils and GRO-managed soils and a biological one for characterizing soil functionality and ecotoxicity. Soil samples from field studies representing one of the main GROs (phytoextraction in Belgium, Sweden, Germany and Switzerland, aided phytoextraction in France, and aided phytostabilization or in situ stabilization/phytoexclusion in Poland, France and Austria) were collected and assessed using the selected test batteries. The best correlations were obtained between NH4NO3-extractable, followed by NaNO3-extractable TE and the ecotoxicological responses. Biometrical parameters and biomarkers of dwarf beans were the most responsive indicators for the soil treatments and changes in soil TE exposures. Plant growth was inhibited at the higher extractable TE concentrations, while plant stress enzyme activities increased with the higher TE extractability. Based on these results, a minimum risk assessment battery to compare/biomonitor the sites phytomanaged by GROs might consist of the NH4NO3 extraction and the bean Plantox test including the stress enzyme activities. Copyright © 2014 Elsevier B.V. All rights reserved.
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Dallas, Lorna J; Devos, Alexandre; Fievet, Bruno; Turner, Andrew; Lyons, Brett P; Jha, Awadhesh N
2016-05-01
Accurate dosimetry is critically important for ecotoxicological and radioecological studies on the potential effects of environmentally relevant radionuclides, such as tritium ((3)H). Previous studies have used basic dosimetric equations to estimate dose from (3)H exposure in ecologically important organisms, such as marine mussels. This study compares four different methods of estimating dose to adult mussels exposed to 1 or 15 MBq L(-1) tritiated water (HTO) under laboratory conditions. These methods were (1) an equation converting seawater activity concentrations to dose rate with fixed parameters; (2) input into the ERICA tool of seawater activity concentrations only; (3) input into the ERICA tool of estimated whole organism concentrations (woTACs), comprising dry activity plus estimated tissue free water tritium (TFWT) activity (TFWT volume × seawater activity concentration); and (4) input into the ERICA tool of measured whole organism activity concentrations, comprising dry activity plus measured TFWT activity (TFWT volume × TFWT activity concentration). Methods 3 and 4 are recommended for future ecotoxicological experiments as they produce values for individual animals and are not reliant on transfer predictions (estimation of concentration ratio). Method 1 may be suitable if measured whole organism concentrations are not available, as it produced results between 3 and 4. As there are technical complications to accurately measuring TFWT, we recommend that future radiotoxicological studies on mussels or other aquatic invertebrates measure whole organism activity in non-dried tissues (i.e. incorporating TFWT and dry activity as one, rather than as separate fractions) and input this data into the ERICA tool. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Present constraints on the H-dibaryon at the physical point from Lattice QCD
Beane, S. R.; Chang, E.; Detmold, W.; ...
2011-11-10
The current constraints from Lattice QCD on the existence of the H-dibaryon are discussed. With only two significant Lattice QCD calculations of the H-dibaryon binding energy at approximately the same lattice spacing, the form of the chiral and continuum extrapolations to the physical point are not determined. In this brief report, an extrapolation that is quadratic in the pion mass, motivated by low-energy effective field theory, is considered. An extrapolation that is linear in the pion mass is also considered, a form that has no basis in the effective field theory, but is found to describe the light-quark mass dependencemore » observed in Lattice QCD calculations of the octet baryon masses. In both cases, the extrapolation to the physical pion mass allows for a bound H-dibaryon or a near-threshold scattering state.« less
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Rattner, B.A.; Ackerson, B.K.
2006-01-01
Based upon these and other findings, ecotoxicological monitoring and research investigations of terrestrial vertebrates are warranted at several National Parks. These include Shenandoah National Park, Richmond National Battlefield, Chesapeake & Ohio Canal National Historic Park, Valley Forge National Historic Park, Hopewell Furnace National Historic Site, Monocacy National Battlefield, and Harpers Ferry National Historic Park. The types of investigations vary according to the species present at these parks and potential contaminant threats, but should focus on contemporary use pesticides and herbicides, polychlorinated biphenyls, mercury, lead, and perhaps, emerging contaminants including antibiotics, flame retardants, pharmaceuticals, and surfactants. Other management recommendations include additional training for natural resource staff members in the area of ecotoxicology, inclusion of terrestrial vertebrate contaminant monitoring and the Contaminant Assessment Process (U.S. Geological Survey Biomonitoring of Environmental Status and Trends Project) into the National Park Service Vital Signs Program, development of protocols for hand ling and toxicological analysis of dead or seemingly affected wildlife, consideration of some alternative methods and compounds for pest management and weed control, and use of non-toxic fishing tackle by visitors.
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Sanchez, W; Palluel, O; Lagadic, L; Aït-Aïssa, S; Porcher, J-M
2006-07-01
This study examined the response of 7-ethoxyresorufine-O-deethylase, glutathione-S-transferase, glutathione peroxidase, glutathione content, level of thiobarbituric acid reactive compounds and circulating vitellogenin, in three-spined sticklebacks after 21 days of exposure to Diquat herbicide, commercial nonylphenol polyethoxylate adjuvant and mixture between Diquat and adjuvant. The results showed that adjuvant exerted more important oxidative effects than Diquat and that mixture effects were unlike to single additivity. This study argues for ecotoxicological risk assessment of adjuvants and mixtures of adjuvants and pesticides.
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Profound Effects of Population Density on Fitness-Related Traits in an Invasive Freshwater Snail
Zachar, Nicholas; Neiman, Maurine
2013-01-01
Population density can profoundly influence fitness-related traits and population dynamics, and density dependence plays a key role in many prominent ecological and evolutionary hypotheses. Here, we evaluated how individual-level changes in population density affect growth rate and embryo production early in reproductive maturity in two different asexual lineages of Potamopyrgus antipodarum, a New Zealand freshwater snail that is an important model system for ecotoxicology and the evolution of sexual reproduction as well as a potentially destructive worldwide invader. We showed that population density had a major influence on individual growth rate and early-maturity embryo production, effects that were often apparent even when comparing treatments that differed in population density by only one individual. While individual growth rate generally decreased as population density increased, we detected a hump-shaped relationship between embryo production and density, with females from intermediate-density treatments producing the most embryos and females from low- and high-density treatments producing the fewest embryos. The two lineages responded similarly to the treatments, indicating that these effects of population density might apply more broadly across P. antipodarum. These results indicate that there are profound and complex relationships between population density, growth rate, and early-maturity embryo production in at least two lineages of this important model system, with potential implications for the study of invasive populations, research on the maintenance of sex, and approaches used in ecotoxicology. PMID:24278240
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Profound effects of population density on fitness-related traits in an invasive freshwater snail.
Zachar, Nicholas; Neiman, Maurine
2013-01-01
Population density can profoundly influence fitness-related traits and population dynamics, and density dependence plays a key role in many prominent ecological and evolutionary hypotheses. Here, we evaluated how individual-level changes in population density affect growth rate and embryo production early in reproductive maturity in two different asexual lineages of Potamopyrgus antipodarum, a New Zealand freshwater snail that is an important model system for ecotoxicology and the evolution of sexual reproduction as well as a potentially destructive worldwide invader. We showed that population density had a major influence on individual growth rate and early-maturity embryo production, effects that were often apparent even when comparing treatments that differed in population density by only one individual. While individual growth rate generally decreased as population density increased, we detected a hump-shaped relationship between embryo production and density, with females from intermediate-density treatments producing the most embryos and females from low- and high-density treatments producing the fewest embryos. The two lineages responded similarly to the treatments, indicating that these effects of population density might apply more broadly across P. antipodarum. These results indicate that there are profound and complex relationships between population density, growth rate, and early-maturity embryo production in at least two lineages of this important model system, with potential implications for the study of invasive populations, research on the maintenance of sex, and approaches used in ecotoxicology.
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Sanderson, Hans; Thomsen, Marianne
2009-06-01
Pharmaceuticals have been reported to be ubiquitously present in surface waters prompting concerns of effects of these bioactive substances. Meanwhile, there is a general scarcity of publicly available ecotoxicological data concerning pharmaceuticals. The aim of this paper was to compile a comprehensive database based on OECD's standardized measured ecotoxicological data and to evaluate if there is generally cause of greater concern with regards to pharmaceutical aquatic toxicological profiles relative to industrial chemicals. Comparisons were based upon aquatic ecotoxicity classification under the United Nations Global Harmonized System for classification and labeling of chemicals (GHS). Moreover, we statistically explored whether the predominant mode-of-action (MOA) for pharmaceuticals is narcosis. We found 275 pharmaceuticals with 569 acute aquatic effect data; 23 pharmaceuticals had chronic data. Pharmaceuticals were found to be more frequent than industrial chemicals in GHS category III. Acute toxicity was predictable (>92%) using a generic (Q)SAR ((Quantitative) Structure Activity Relationship) suggesting a narcotic MOA. Analysis of model prediction error suggests that 68% of the pharmaceuticals have a non-specific MOA. Additionally, the acute-to-chronic ratio (ACR) for 70% of the analyzed pharmaceuticals was below 25 further suggesting a non-specific MOA. Sub-lethal receptor-mediated effects may however have a more specific MOA.
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Martín-Díaz, M Laura; Gagné, François; Blaise, Christian
2009-09-01
A biomarker approach was undertaken using the mussel Elliptio complanata to assess the ecotoxicological effects after injection of a range concentration (0-10mM) of three different PPCPs: carbamazepine, caffeine, methotrexate; and an effluent extract (C8) from St. Lawrence wastewaters treatment plant (Montreal, Canada). A battery of biomarkers, involving oxidative stress and genotoxicity responses: glutation-S-transferase (GST), ethoxyresorufin O-deethylase (EROD), dibenzylflourescein dealkylase (DBF), xanthine oxidoreductase (XOR) activities, lipid peroxidation (LPO) and DNA damage were determined in gonad and digestive gland tissues after 48 h of injection. Results showed an induction of the oxidative metabolism with increasing pharmaceutical concentration in those mussels injected with the PPCPs and the effluent extract. Phase I detoxification enzymes were significantly induced (p<0.05), concretely DBF activity was significantly induced after caffeine, carbamazipine and C8 injection; and EROD activity after C8 and methotrexate injection. Oxidative stress induction only lead to lipid peroxidation (p<0.05) in organisms injected with carbamazepine and caffeine and DNA damage in organisms injected with methotrexate (p<0.05). EROD and DBF enzymatic activities have been found to be suitable biomarkers to determine bioavailability of pharmaceuticals. LPO and DNA damage to determine possible associated adverse effects. Nevertheless, their validation in realistic exposure scenarios and under exposure conditions should be performed in future research.
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NASA Astrophysics Data System (ADS)
Troppová, Ivana; Matějová, Lenka; Sezimová, Hana; Matěj, Zdeněk; Peikertová, Pavlína; Lang, Jaroslav
2017-06-01
The eco-toxicological effects of unconventionally prepared nanostructured TiO2 and ZnO were evaluated in this study, since both oxides are keenly investigated semiconductor photocatalysts in the last three decades. Unconventional processing by pressurized hot water was applied in order to crystallize oxide materials as an alternative to standard calcination. Acute biological toxicity of the synthesized oxides was evaluated using germination of Sinapis alba seed (ISO 11269-1) and growth of Lemna minor fronds (ISO 20079) and was compared to commercially available TiO2 Degussa P25. Toxicity results revealed that synthesized ZnO as well as TiO2 is toxic contrary to commercial TiO2 Degussa P25 which showled stimulation effect to L. minor and no toxicity to S. alba. ZnO was significantly more toxic than TiO2. The effect of crystallite size was considered, and it was revealed that small crystallite size and large surface area are not the toxicity-determining factors. Factors such as the rate of nanosized crystallites aggregation and concentration, shape and surface properties of TiO2 nanoparticles affect TiO2 toxicity to both plant species. Seriously, the dissolution of Ti4+ ions from TiO2 was also observed which may contribute to its toxicity. In case of ZnO, the dissolution of Zn2+ ions stays the main cause of its toxicity.
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de Vries, Wim; Lofts, Steve; Tipping, Ed; Meili, Markus; Groenenberg, Jan E; Schütze, Gudrun
2007-01-01
Risk assessment for metals in terrestrial ecosystems, including assessments of critical loads, requires appropriate critical limits for metal concentrations in soil and soil solution. This chapter presents an overview of methodologies used to derive critical (i) reactive and total metal concentrations in soils and (ii) free metal ion and total metal concentrations in soil solution for Cd, Pb, Cu, Zn, and Hg, taking into account the effect of soil properties related to ecotoxicological effects. Most emphasis is given to the derivation of critical free and total metal concentrations in soil solution, using available NOEC soil data and transfer functions relating solid-phase and dissolved metal concentrations. This approach is based on the assumption that impacts on test organisms (plants, microorganisms, and soil invertebrates) are mainly related to the soil solution concentration (activity) and not to the soil solid-phase content. Critical Cd, Pb, Cu, Zn, and Hg concentrations in soil solution vary with pH and DOC level. The results obtained are generally comparable to those derived for surface waters based on impacts to aquatic organisms. Critical soil metal concentrations, related to the derived soil solution limits, can be described as a function of pH and organic matter and clay content, and varying about one order of magnitude between different soil types.
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Review of the ecotoxicological effects of emerging contaminants to soil biota.
Gomes, Ana R; Justino, Celine; Rocha-Santos, Teresa; Freitas, Ana C; Duarte, Armando C; Pereira, Ruth
2017-08-24
In recent years, emerging contaminants (e.g. pesticides and their metabolites, pharmaceuticals, personal and house care products, life-style compounds, food additives, industrial products and wastes, as well as nanomaterials) have become a problem to the environment. In fact, the cumulative use of a panoply of chemical substances in agriculture, industrial activities, in our homes and in health care services has led to their recent appearance in detectable levels in soils, surface, and groundwater resources, with unpredictable consequences for these ecosystems. Few data exist regarding the toxicity and potential for bioaccumulation in biota. When available, data were obtained only for some representatives of the main groups of chemical substances, and for a limited number of species, following non-standard protocols. This makes difficult the calculation of predicted no effect concentrations (PNEC) and the existence of sufficient data to set limits for their release into the environment. This is particularly concerning for the soil compartment, since only recently the scientific community, regulators, and the public have realised the importance of protecting this natural resource and its services to guarantee the sustainability of terrestrial ecosystems and human well-being. In this context, this review paper aims to identify the major groups of soil emerging contaminants, their sources, pathways and receptors, and in parallel to analyse existing ecotoxicological data for soil biota.
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Effects of gamma radiation on the early developmental stages of Zebrafish (Danio rerio).
Praveen Kumar, M K; Shyama, S K; Kashif, Shamim; Dubey, S K; Avelyno, D'costa; Sonaye, B H; Kadam Samit, B; Chaubey, R C
2017-08-01
The zebrafish is gaining importance as a popular vertebrate model organism and is widely employed in ecotoxicological studies, especially for the biomonitoring of pollution in water bodies. There is limited data on the genetic mechanisms governing the adverse health effects in regards to an early developmental exposure to gamma radiation. In the present study zebrafish (Danio rerio) embryos were exposed to 1, 2.5, 5, 7.5 and 10Gy of gamma radiation at 3h post fertilization (hpf). Different developmental toxicity endpoints were investigated. Further, expression of genes associated with the development and DNA damage i.e. (sox2 sox19a and p53) were evaluated using Quantitative PCR (qPCR). The significant changes in the expression of sox2 sox19a and p53 genes were observed. This data was supported the developmental defects observed in the zebrafish embryo exposed to gamma radiation such as i.e. increased DNA damage, decreased hatching rate, increase in median hatching time, decreased body length, increased mortality rate, increased morphological deformities. Further, study shows that the potential ecotoxicological threat of gamma radiation on the early developmental stages of zebrafish. Further, it revealed that the above parameters can be used as predictive biomarkers of gamma radiation exposure. Copyright © 2017. Published by Elsevier Inc.
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Assessing the toxicity and biodegradability of deep eutectic solvents.
Wen, Qing; Chen, Jing-Xin; Tang, Yu-Lin; Wang, Juan; Yang, Zhen
2015-08-01
Deep eutectic solvents (DESs) have emerged as a new type of promising ionic solvents with a broad range of potential applications. Although their ecotoxicological profile is still poorly known, DESs are generally regarded as "green" because they are composed of ammonium salts and H-bond donors (HBDs) which are considered to be eco-friendly. In this work, cholinium-based DESs comprised of choline chloride (ChCl) and choline acetate (ChAc) as the salt and urea (U), acetamide (A), glycerol (G) and ethylene glycol (EG) as the HBD were evaluated for their toxic effects on different living organisms such as Escherichia coli (a bacterium), Allium sativum (garlic, a plant) and hydra (an invertebrate), and their biodegradabilities were assessed by means of closed bottle tests. These DESs possessed an anti-bacterial property and exhibited inhibitory effects on the test organisms adopted, depending on the composition and concentration of the DES. The mechanism for the impact of DESs and their components on different living organisms can be associated to their interactions with the cellular membranes. Not all DESs can be considered readily biodegradable. By extending the limited knowledge about the toxicity and biodegradation of this particular solvent family, this investigation on DESs provides insight into our structure-based understanding of their ecotoxicological behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Yamamoto, Tetsuya
2007-06-01
A novel test fixture operating at a millimeter-wave band using an extrapolation range measurement technique was developed at the National Metrology Institute of Japan (NMIJ). Here I describe the measurement system using a Q-band test fixture. I measured the relative insertion loss as a function of antenna separation distance and observed the effects of multiple reflections between the antennas. I also evaluated the antenna gain at 33 GHz using the extrapolation technique.
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Effective orthorhombic anisotropic models for wavefield extrapolation
NASA Astrophysics Data System (ADS)
Ibanez-Jacome, Wilson; Alkhalifah, Tariq; Waheed, Umair bin
2014-09-01
Wavefield extrapolation in orthorhombic anisotropic media incorporates complicated but realistic models to reproduce wave propagation phenomena in the Earth's subsurface. Compared with the representations used for simpler symmetries, such as transversely isotropic or isotropic, orthorhombic models require an extended and more elaborated formulation that also involves more expensive computational processes. The acoustic assumption yields more efficient description of the orthorhombic wave equation that also provides a simplified representation for the orthorhombic dispersion relation. However, such representation is hampered by the sixth-order nature of the acoustic wave equation, as it also encompasses the contribution of shear waves. To reduce the computational cost of wavefield extrapolation in such media, we generate effective isotropic inhomogeneous models that are capable of reproducing the first-arrival kinematic aspects of the orthorhombic wavefield. First, in order to compute traveltimes in vertical orthorhombic media, we develop a stable, efficient and accurate algorithm based on the fast marching method. The derived orthorhombic acoustic dispersion relation, unlike the isotropic or transversely isotropic ones, is represented by a sixth order polynomial equation with the fastest solution corresponding to outgoing P waves in acoustic media. The effective velocity models are then computed by evaluating the traveltime gradients of the orthorhombic traveltime solution, and using them to explicitly evaluate the corresponding inhomogeneous isotropic velocity field. The inverted effective velocity fields are source dependent and produce equivalent first-arrival kinematic descriptions of wave propagation in orthorhombic media. We extrapolate wavefields in these isotropic effective velocity models using the more efficient isotropic operator, and the results compare well, especially kinematically, with those obtained from the more expensive anisotropic extrapolator.
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ERIC Educational Resources Information Center
Wolfe, Mary L.; Martuza, Victor R.
The major purpose of this experiment was to examine the effects of format (bar graphs vs. tables) and organization (by year vs. by brand) on the speed and accuracy of extrapolation and interpolation with multiple, nonlinear trend displays. Fifty-six undergraduates enrolled in the College of Education at the University of Delaware served as the…
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Effect of soil compaction on the degradation and ecotoxicological impact of isoproturon
NASA Astrophysics Data System (ADS)
Mamy, L.; Vrignaud, P.; Cheviron, N.; Perreau, F.; Belkacem, M.; Brault, A.; Breuil, S.; Delarue, G.; Touton, I.; Chaplain, V.
2009-04-01
Soil is essentially a non-renewable resource which performs many functions and delivers services vital to human activities and ecosystems survival. However the capacity of soil to keep on fully performing its broad variety of crucial functions is damaged by several threats and, among them, chemical contamination by pesticides and compaction due to intensive agriculture practices. How these two threats could interact is largely unknown: compaction may modify the fate of pesticides in soil therefore their effects on the biological functioning of soil. The aim of this work was to study the effect of soil compaction on (1) the degradation of one herbicide, isoproturon (2) the ecotoxicological impact of this herbicide measured through two enzyme activities involved in C (beta-glucosidase) and N (urease) cycles in soil. Undisturbed soil cylinders were sampled in the 2-4 cm layer of La Cage experimental site (INRA, Versailles, France), under intensive agriculture practices. Several soil samples were prepared with different bulk density then treated with isoproturon (IPU). The samples were incubated at 18 ± 1°C in darkness for 63 days. At 0, 2, 7, 14, 28 and 63 days, the concentrations of isoproturon and of two of its main metabolites in soil (monodesmethyl-isoproturon, IPPMU; didesmethyl-isoproturon, IPPU), and the enzyme activities were measured. The results showed that there was no significant difference in IPU degradation under no and moderate soil compaction. IPU was less persistent in the highly compacted soil, but this soil had also higher humidity which is known to increase the degradation. Only one metabolite, IPPMU, was detected independently of the conditions of compaction. The compaction did not modify the effect of IPU on beta-glucosidase and urease activities in the long term, but microbial communities were probably the same in all the soil samples that were initially not compacted. The communities developed in durably compacted zones in the field are possibly different and modification in enzyme activities might be observed as a result. These first results seem to show that compaction did not modify the degradation and ecotoxicological impact of isoproturon in the soil. However, further studies should be performed using soil samples taken in different zones of compaction in the field, and taking into account the relation between bulk density and soil humidity.
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Ecotoxicological risk assessment of environmental pollutants in the Arctic.
Brunström, B; Halldin, K
2000-03-15
Concentrations of such persistent organic pollutants (POPs) as polychlorinated biphenyls (PCBs) are high in certain Arctic animal species. The polar bear, Arctic fox, and glaucous gull may be exposed to PCB levels above lowest-observed-adverse-effect-level (LOAEL) values for adverse effects on reproduction in mammals and birds. However, the dioxin-like congeners seem to be major contributors to the reproductive effects of PCBs and the relative concentrations of these congeners are low in polar bears. Temporal trends for POPs in Arctic wildlife and the sensitivities of Arctic species to these compounds determine the risk for future adverse health effects.
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Toxicity of organic UV-filters to the aquatic midge Chironomus riparius.
Campos, Diana; Gravato, Carlos; Quintaneiro, Carla; Golovko, Oksana; Žlábek, Vladimír; Soares, Amadeu M V M; Pestana, João L T
2017-09-01
Despite the frequent detection of organic ultraviolet-filters (UV-filters) in freshwater sediments, there is a lack of ecotoxicological data undermining a correct risk assessment for these emerging contaminants. The present study assessed the effects of three of the most commonly used UV-filters (benzophenone-3 - BP3; 3-(4-methylbenzylidene)camphor - 4-MBC and octocrylene - OC) on Chironomus riparius life history and biochemical responses. Standard ecotoxicological assays confirmed that all compounds impaired growth of C. riparius larvae and induced developmental effects such as delayed emergence and a reduction of imagoes weight. Concerning the biochemical responses analysed no evidences of oxidative damage in lipids or neurotoxicity (tested assessing acetylcholinesterase activity) were observed for any of the tested compounds. However, 4-MBC exposure induced a decrease in catalase activity and an increase in glutathione-S-transferase activity at 14.13mg/Kg while OC exposure caused an increase in total glutathione levels at 0.23 and 18.23mg/Kg. Exposure to all UV-filters tested, increased energy consumption on C. riparius with significant differences above 1.00mg/Kg for BP3, 0.09mg/Kg for 4-MBC and 2.13mg/Kg for OC. These results suggest that environmental relevant concentrations of UV-filters can cause deleterious effects to aquatic benthic species, such as C. riparius, and call for further research concerning effects of organic UV-filters on natural invertebrate communities and ecosystem functioning. Copyright © 2017 Elsevier Inc. All rights reserved.
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Walvekar, Varsha Ashok; Bajaj, Swati; Singh, Dileep K; Sharma, Shilpi
2017-07-01
India is one of the leading countries in production and indiscriminate consumption of pesticides. Owing to their xenobiotic nature, pesticides affect soil microorganisms that serve as mediators in plant growth promotion. Our study aimed to deliver a comprehensive picture, by comparing the effects of synthetic pesticides (chlorpyriphos, cypermethrin, and a combination of both) with a biopesticide (azadirachtin) at their recommended field application level (L), and three times the recommended dosage (H) on structure and function of microbial community in rhizosphere of Vigna radiata. Effect on culturable fraction was assessed by enumeration on selective media, while PCR-denaturing gradient gel electrophoresis (DGGE) was employed to capture total bacterial community diversity. This was followed by a metabolic sketch using community-level physiological profiling (CLPP), to obtain a broader picture of the non-target effects on rhizospheric microbial community. Although plant parameters were not significantly affected by pesticide application, the microbial community structure experienced an undesirable impact as compared to control devoid of pesticide treatment. Examination of DGGE banding patterns through cluster analysis revealed that microbial community structure of pesticide-treated soils had only 70% resemblance to control rhizospheric soil even at 45 days post application. Drastic changes in the metabolic profiles of pesticide-treated soils were also detected in terms of substrate utilization, rhizospheric diversity, and evenness. It is noteworthy that the effects exacerbated by biopesticide were comparable to that of synthetic pesticides, thus emphasizing the significance of ecotoxicological assessments before tagging biopesticides as "safe alternatives."
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NASA Astrophysics Data System (ADS)
Domínguez, Anahí; Pía Rodríguez, María; Ortiz, Carolina Elizabeth; Camilo Bedano, José
2017-04-01
Ecosystem engineers are organisms that modulate the availability of resources to other species by causing physical state changes in biotic or abiotic materials. In the agricultural soils of the Pampa region of Argentina, earthworms are undoubtedly the key soil ecosystem engineers. Indeed, earthworms are involved in building and maintenance of porosity through bioturbation and burrowing; comminution, selection and or activation of microflora activities and in soil formation, by bioturbation, cast deposition and particle selection. Attending to the importance of such processes to preserve the soil capacity to sustain crop productivity, the promotion of suitable habitats for earthworm communities, has become a main goal for sustainable agriculture. However, in Argentine Pampas, the impact of the huge amount of pesticides currently spread on farming soils, on the earthworm biology and ecology, is scarcely considered when agricultural managements practices are selected. In fact, more than 250 million liters of glyphosate-based herbicides are spread by year in the farming soils of Argentina. Glyphosate has a relative short half-life, but one of the major breakdown products, the aminomethylphosphonic acid (AMPA), is persistent in soils. We tested its toxicity1 on the earthworm Eisenia andrei, and we found no mortality but growth and reproductive disorders. However, E. andrei is seldom found in agricultural lands. Indeed, for the last 8 years, we have sampled an important variety of agricultural soils, representing the most important farming systems used in Argentina, and we never found Eisenia spp. but 13 earthworm species: 8 exotic from Lumbricidae and 5 natives from Acanthodrilidae, Glossoscolecidae and Ocnerodrilidae families. However, the ecotoxicological effect of glyphosate has been detailed studied only in three of the mentioned exotic species, and only in four studies2,3,4,5. Such a few studies and a few species indicates a real lack of accurate knowledge about the ecotoxicological effect of glyphosate on the most distributed earthworm species in our country. Moreover, the effect of AMPA on these species is unknown. In this context, we acknowledge the urgent need for performing a deep research on the ecotoxicological effects of glyphosate-based herbicides and their metabolites on native and exotic but abundant earthworm species inhabiting farming soils in Argentina. Moreover, in addition to the classical ecotoxicological test, we are interested in studying the impact of glyphosate-based herbicides on soil ecosystem engineering, by means of a mesocosm approach assessing the production of biogenic structures by earthworms (casts and galleries) at different dosses of herbicides and considering different soils and crops. (1) Domínguez, A. et al. 2016. Sci. Rep. 6, 19731; doi: 10.1038/srep19731. (2) Gaupp-Berghausen, M. et al. 2015. Sci. Rep. 5, 12886; doi: 10.1038/srep12886. (3) Springett, J.A. & R.A.J. Gray. 1992. Soil Biol. Biochem. 24 (12): 1739-1744. (4) Salvio, C. et al. 2016. Bull Environ Contam Toxicol 96:314-319. (5) Garcia Torres, T. et al. Bull Environ Contam Toxicol; doi: 10.1007/s00128-014-1312-8.
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STRESSOR-RESPONSE RELATIONSHIPS: THE FOUNDATION FOR CHARACTERIZING EFFECTS
This research has 4 main components. The first focuses on developing the scientific information needed to extrapolate data from one or a few tested species to species of primary concern, e.g., the need to extrapolate data from domesticated birds to piscivorous avian species when...
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Recent research on the acute effects of volatile organic compounds (VQCs) suggests that extrapolation from short (~ 1 h) to long durations (up to 4 h) may be improved by using estimates of brain toluene concentration (Br[Tol]) instead of cumulative inhaled dose (C x t) as a metri...
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Bachmann, Talis; Murd, Carolina; Põder, Endel
2012-09-01
One fundamental property of the perceptual and cognitive systems is their capacity for prediction in the dynamic environment; the flash-lag effect has been considered as a particularly suggestive example of this capacity (Nijhawan in nature 370:256-257, 1994, Behav brain sci 31:179-239, 2008). Thus, because of involvement of the mechanisms of extrapolation and visual prediction, the moving object is perceived ahead of the simultaneously flashed static object objectively aligned with the moving one. In the present study we introduce a new method and report experimental results inconsistent with at least some versions of the prediction/extrapolation theory. We show that a stimulus moving in the opposite direction to the reference stimulus by approaching it before the flash does not diminish the flash-lag effect, but rather augments it. In addition, alternative theories (in)capable of explaining this paradoxical result are discussed.
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Buckler, Denny R., Foster L. Mayer, Mark R. Ellersieck and Amha Asfaw. 2003. Evaluation of Minimum Data Requirements for Acute Toxicity Value Extrapolation with Aquatic Organisms. EPA/600/R-03/104. U.S. Environmental Protection Agency, National Health and Environmental Effects Re...
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Increased identification of veterinary pharmaceutical contaminants in aquatic environments has raised concerns regarding potential adverse effects of these chemicals on non-target organisms. The purpose of this work was to develop a method for predictive species extrapolation ut...
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A Comparison of Methods for Computing the Residual Resistivity Ratio of High-Purity Niobium
Splett, J. D.; Vecchia, D. F.; Goodrich, L. F.
2011-01-01
We compare methods for estimating the residual resistivity ratio (RRR) of high-purity niobium and investigate the effects of using different functional models. RRR is typically defined as the ratio of the electrical resistances measured at 273 K (the ice point) and 4.2 K (the boiling point of helium at standard atmospheric pressure). However, pure niobium is superconducting below about 9.3 K, so the low-temperature resistance is defined as the normal-state (i.e., non-superconducting state) resistance extrapolated to 4.2 K and zero magnetic field. Thus, the estimated value of RRR depends significantly on the model used for extrapolation. We examine three models for extrapolation based on temperature versus resistance, two models for extrapolation based on magnetic field versus resistance, and a new model based on the Kohler relationship that can be applied to combined temperature and field data. We also investigate the possibility of re-defining RRR so that the quantity is not dependent on extrapolation. PMID:26989580
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Fry, R.J.M.
The author discusses some examples of how different experimental animal systems have helped to answer questions about the effects of radiation, in particular, carcinogenesis, and to indicate how the new experimental model systems promise an even more exciting future. Entwined in these themes will be observations about susceptibility and extrapolation across species. The hope of developing acceptable methods of extrapolation of estimates of the risk of radiogenic cancer increases as molecular biology reveals the trail of remarkable similarities in the genetic control of many functions common to many species. A major concern about even attempting to extrapolate estimates of risksmore » of radiation-induced cancer across species has been that the mechanisms of carcinogenesis were so different among different species that it would negate the validity of extrapolation. The more that has become known about the genes involved in cancer, especially those related to the initial events in carcinogenesis, the more have the reasons for considering methods of extrapolation across species increased.« less
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El-Temsah, Yehia S; Joner, Erik J
2013-06-01
Nano-sized zero valent iron (nZVI) has been studied for in situ remediation of contaminated soil and ground water. However, little is known about its effects on organisms in soil and aquatic ecosystems. In this study, the effect of nZVI on degradation of DDT and its ecotoxicological effects on collembola (Folsomia candida) and ostracods (Heterocypris incongruens) were investigated. Two soils were used in suspension incubation experiments lasting for 7 and 30 d; a spiked (20 mg DDT kg(-1)) sandy soil and an aged (>50 years) DDT-polluted soil (24 mg DDT kg(-1)). These were incubated with 1 or 10 g nZVI kg(-1), and residual toxicity in soil and the aqueous phase tested using ecotoxicological tests with collembola or ostracods. Generally, addition of either concentration of nZVI to soil led to about 50% degradation of DDT in spiked soil at the end of 7 and 30 d incubation, while the degradation of DDT was less in aged DDT-polluted soil (24%). Severe negative effects of nZVI were observed on both test organisms after 7 d incubation, but prolonged incubation led to oxidation of nZVI which reduced its toxic effects on the tested organisms. On the other hand, DDT had significant negative effects on collembolan reproduction and ostracod development. We conclude that 1 g nZVI kg(-1) was efficient for significant DDT degradation in spiked soil, while a higher concentration was necessary for treating aged pollutants in soil. The adverse effects of nZVI on tested organisms seem temporary and reduced after oxidation. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Vincze, Krisztina; Gehring, Martin; Braunbeck, Thomas
2014-01-01
2,4,7,9-tetramethyl-5-decyne-4,7-diol (TMDD) is a high-production volume chemical used in paper, ink, pesticide, and adhesive industries as a wetting and anti-foaming agent. The physicochemical properties and slow biodegradation rate of TMDD indicate a low bioaccumulation potential but a high prevalence in the environment. As a consequence, TMDD has been detected in several European rivers in the nanogram per liter and lower microgram per liter range; however, its environmental risk to aquatic organisms is considered low. Recent studies almost exclusively focused on acute effects by TMDD, little is known about cytotoxic and genotoxic effects, reproduction and developmental toxicity, endocrine disruption, and any kind of long-term toxicity and carcinogenicity so far. The present study aims to provide more specific baseline information on the ecotoxicological effects of TMDD in fish. For this end, cyto- and genotoxicity assays were carried out in vitro with the permanent fish cell line RTL-W1; in addition, in vivo studies were conducted with the early life stages of zebrafish (Danio rerio) in order to fill the data gaps in developmental toxicity and endocrine disruption. TMDD showed a cytotoxic and slight genotoxic potential in fish cell lines; moreover, various sublethal and lethal effects could be detected in developing zebrafish embryos. There was no evidence of endocrine-disrupting effects by TMDD; however, mortality following prolonged exposure to TMDD during fish sexual development test was clearly higher than mortality in the fish embryo test after 96-h exposure. Our results thus confirmed previous findings of laboratory screening tests, suggesting short-term toxic effects of TMDD in the intermediate, and long-term effects in the lower milligram per liter range.
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Chen, Pei-Jen; Wu, Wan-Lin; Wu, Kevin Chia-Wen
2013-08-01
Nanoscale zerovalent iron (nZVI)-mediated oxidation reaction is increasingly being used for enhanced treatment of water or wastewater processes; however, the fate and eco-toxicological effects of nZVI in the surface aquifer remain unclear. We investigated bioaccumulation and lethal-to-sublethal toxic effects on early life development of Japanese medaka (Oryzias latipes) with 7-day exposure to 25-200 mg/L of well-characterized solutions containing carboxymethyl cellulose (CMC)-stabilized nZVI (CMC-nZVI), nanoscale iron oxide (nFe3O4) or ferrous ion [Fe(II)aq]. The CMC-nZVI solution had the greatest acute mortality and developmental toxic effects in embryos, with lesser and the least effects with Fe(II)aq and nFe3O4. The toxicity of CMC-nZVI was ascribed to its high reactivity in the oxygenic solution, which led to a combination of hypoxia and production of reactive oxygen species (ROS) and Fe(II)aq. nFe3O4 (50-100 mg/L) was more bioavailable to embryos and bioaccmulative in hatchlings than suspended CMC-nZVI. The antioxidant balance was differentially altered by induced intracellular ROS in hatchlings with all 3 iron species. We revealed causal toxic effects of nZVI and its oxidized products in early life stages of medaka fish using different organizational levels of biomarker assays. The toxicity results implicate a potential eco-toxicological impact of nZVI on the aquatic environment. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Soil quality in the Lomellina area using in vitro models and ecotoxicological assays
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baderna, Diego, E-mail: diego.baderna@marionegri.it; Colombo, Andrea; Romeo, Margherita
2014-08-15
Soil quality is traditionally evaluated by chemical characterization to determine levels of pollutants. Biological tools are now employed for soil monitoring since they can take account of the global biological effects induced by all xenobiotics. A combined monitoring of soils based on chemical analyses, human-related in vitro models and ecotoxicological assay was applied in the Lomellina, a semirural area of northern Italy. Chemical characterization indicated overall good quality of the soils, with low levels of toxic and carcinogenic pollutants such as heavy metals, PAHs, PCDD/Fs and PCBs. HepG2 cells were used as a model for the human liver and BALB/cmore » 3T3 cells to evaluate carcinogenic potential. Cells were treated with soil extractable organic matter (EOM) and the MTS assay, DNA release and morphological transformation were selected as endpoints for toxicity and carcinogenicity. Soil EOMs induced dose-dependent inhibition of cell growth at low doses and cytotoxicity only at doses of 500 and 1000 mg soil equivalents/ml. Potential issues for human health can be hypothesized after ingestion of soil samples from some sites. No statistically significant inductions of foci were recorded after exposure to EOMs, indicating that the levels of the soil-extracted organic pollutants were too low to induce carcinogenesis in our experimental conditions. An acute phytotoxicity test and studies on Caenorhabditis elegans were used as ecotoxicological assays for plants and small invertebrates. No significant alerts for ecotoxicity were found. In this proposed case study, HepG2 cells detected differences in the toxicity of soil EOMs, indicating that this cell line could be appropriate to assess the potential harm caused by the ingestion of contaminated soil. Additional information on the carcinogenic potential of mixtures was provided by the cell transformation assay, strengthening the combined approach. - Highlights: • A combined approach for evaluation of soil quality is proposed. • Organic extracts from investigated soils inhibited HepG2 cell proliferation. • The carcinogenic potential of extracts was evaluated by cell transformation assay. • Potential alerts were estimated after ingestion of soils. • Caenorhabditis elegans and phytotest were used to evaluate ecological effects.« less
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In vitro-in vivo extrapolation (IVIVE), or the process of using in vitro data to predict in vivo phenomena, provides key opportunities to bridge the disconnect between high-throughput screening data and real-world human exposures and potential health effects. Strategies utilizing...
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How to Appropriately Extrapolate Costs and Utilities in Cost-Effectiveness Analysis.
Bojke, Laura; Manca, Andrea; Asaria, Miqdad; Mahon, Ronan; Ren, Shijie; Palmer, Stephen
2017-08-01
Costs and utilities are key inputs into any cost-effectiveness analysis. Their estimates are typically derived from individual patient-level data collected as part of clinical studies the follow-up duration of which is often too short to allow a robust quantification of the likely costs and benefits a technology will yield over the patient's entire lifetime. In the absence of long-term data, some form of temporal extrapolation-to project short-term evidence over a longer time horizon-is required. Temporal extrapolation inevitably involves assumptions regarding the behaviour of the quantities of interest beyond the time horizon supported by the clinical evidence. Unfortunately, the implications for decisions made on the basis of evidence derived following this practice and the degree of uncertainty surrounding the validity of any assumptions made are often not fully appreciated. The issue is compounded by the absence of methodological guidance concerning the extrapolation of non-time-to-event outcomes such as costs and utilities. This paper considers current approaches to predict long-term costs and utilities, highlights some of the challenges with the existing methods, and provides recommendations for future applications. It finds that, typically, economic evaluation models employ a simplistic approach to temporal extrapolation of costs and utilities. For instance, their parameters (e.g. mean) are typically assumed to be homogeneous with respect to both time and patients' characteristics. Furthermore, costs and utilities have often been modelled to follow the dynamics of the associated time-to-event outcomes. However, cost and utility estimates may be more nuanced, and it is important to ensure extrapolation is carried out appropriately for these parameters.
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Finite volume effects on the electric polarizability of neutral hadrons in lattice QCD
NASA Astrophysics Data System (ADS)
Lujan, M.; Alexandru, A.; Freeman, W.; Lee, F. X.
2016-10-01
We study the finite volume effects on the electric polarizability for the neutron, neutral pion, and neutral kaon using eight dynamically generated two-flavor nHYP-clover ensembles at two different pion masses: 306(1) and 227(2) MeV. An infinite volume extrapolation is performed for each hadron at both pion masses. For the neutral kaon, finite volume effects are relatively mild. The dependence on the quark mass is also mild, and a reliable chiral extrapolation can be performed along with the infinite volume extrapolation. Our result is αK0 phys=0.356 (74 )(46 )×10-4 fm3 . In contrast, for neutron, the electric polarizability depends strongly on the volume. After removing the finite volume corrections, our neutron polarizability results are in good agreement with chiral perturbation theory. For the connected part of the neutral pion polarizability, the negative trend persists, and it is not due to finite volume effects but likely sea quark charging effects.
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Patange, Apurva; Boehm, Daniela; Giltrap, Michelle; Lu, Peng; Cullen, P J; Bourke, Paula
2018-08-01
Generation of wastewater is one of the main environmental sustainability issues across food sector industries. The constituents of food process effluents are often complex and require high energy and processing for regulatory compliance. Wastewater streams are the subject of microbiological and chemical criteria, and can have a significant eco-toxicological impact on the aquatic life. Thus, innovative treatment approaches are required to mitigate environmental impact in an energy efficient manner. Here, dielectric barrier discharge atmospheric cold plasma (ACP) was evaluated for control of key microbial indicators encountered in food industry effluent. This study also investigated the eco-toxicological impact of cold plasma treatment of the effluents using a range of aquatic bioassays. Continuous ACP treatment was applied to synthetic dairy and meat effluents. Microbial inactivation showed treatment time dependence with significant reduction in microbial populations within 120 s, and to undetectable levels after 300 s. Post treatment retention time emerged as critical control parameter which promoted ACP bacterial inactivation efficiency. Moreover, ACP treatment for 20 min achieved significant reduction (≥2 Log 10 ) in Bacillus megaterium endospores in wastewater effluent. Acute aquatic toxicity was assessed using two fish cell lines (PLHC-1 and RTG-2) and a crustacean model (Daphnia magna). Untreated effluents were toxic to the aquatic models, however, plasma treatment limited the toxic effects. Differing sensitivities were observed to ACP treated effluents across the different test bio-assays in the following order: PLHC-1 > RTG-2 ≥ D. magna; with greater sensitivity retained to plasma treated meat effluent than dairy effluent. The toxic effects were dependent on concentration and treatment time of the ACP treated effluent; with 30% cytotoxicity in D. magna and fish cells observed after 24 h of exposure to ACP treated effluent for concentrations up to 5%. The findings suggest the need to employ wider variety of aquatic organisms for better understanding and complete toxicity evaluation of long-term effects. The study demonstrates the potential to tailor ACP system parameters to control pertinent microbial targets (mono/poly-microbial, vegetative or spore form) found in complex and nutritious wastewater effluents whilst maintaining a safe eco-toxicity profile for aquatic species. Copyright © 2018 Elsevier B.V. All rights reserved.
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Postigo, Cristina; López de Alda, María José; Barceló, Damià
2010-01-01
Drugs of abuse and their metabolites have been recently recognized as environmental emerging organic contaminants. Assessment of their concentration in different environmental compartments is essential to evaluate their potential ecotoxicological effects. It also constitutes an indirect tool to estimate drug abuse by the population at the community level. The present work reports for the first time the occurrence of drugs of abuse and metabolites residues along the Ebro River basin (NE Spain) and also evaluates the contribution of sewage treatment plants (STPs) effluents to the presence of these chemicals in natural surface waters. Concentrations measured in influent sewage waters were used to back calculate drug usage at the community level in the main urban areas of the investigated river basin. The most ubiquitous and abundant compounds in the studied aqueous matrices were cocaine, benzoylecgonine, ephedrine and ecstasy. Lysergic compounds, heroin, its metabolite 6-monoacetyl morphine, and Delta(9)-tetradhydrocannabinol were the substances less frequently detected. Overall, total levels of the studied illicit drugs and metabolites observed in surface water (in the low ng/L range) were one and two orders of magnitude lower than those determined in effluent (in the ng/L range) and influent sewage water (microg/L range), respectively. The investigated STPs showed overall removal efficiencies between 45 and 95%. Some compounds, such as cocaine and amphetamine, were very efficiently eliminated (>90%) whereas others, such as ecstasy, methamphetamine, nor-LSD, and THC-COOH where occasionally not eliminated at all. Drug consumption estimates pointed out cocaine as the most abused drug, followed by cannabis, amphetamine, heroin, ecstasy and methamphetamine, which slightly differs from national official estimates (cannabis, followed by cocaine, ecstasy, amphetamine and heroin). Extrapolation of the consumption data obtained for the studied area to Spain points out a total annual consumption of drugs of abuse of the order of 36 tonnes, which would translate into 1100million Euros in the black market.
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Rattner, B.A.; Shore, R.F.
2000-01-01
An international group of 32 scientists has critically reviewed the scientific literature on exposure and effects of environmental contaminants in wild mammals. Although the absolute number of toxicological studies in domesticated and wild mammals eclipses that for birds, a detailed examination of scientific publications and databases reveal that information for 'wild' birds is actually greater than that for 'wild' mammals. Of the various taxa of mammals, ecotoxicological data is most noticeably lacking for marsupials and monotremes. In contrast, rodents (comprising 43% of all mammal species) have been studied extensively, despite evidence of their tolerance to some organochlorine compounds, rodenticides, and even radionuclides. Mammalian species at greatest risk of exposure include those that consume a high percentage of their body weight on a daily basis (e.g., shrews, moles and bats). Aquatic mammals tend to bioaccumulate tremendous burdens of lipophilic contaminants, although storage in their fat depots may actually limit toxicity. Carnivores appear to be more sensitive to adverse effects of environmental contaminants than herbivores. Remarkably few of the thousands of compounds manufactured worldwide have been toxicologically evaluated in wild mammals, and concentrations of even fewer have been monitored in tissues. Overarching research needs include: development of new exposure/effects models and better methods for estimation of species sensitivities; generation of comparative data on contaminant bioavailability, sublethal responses and detoxication mechanisms; enhanced understanding of pesticide, industrial contaminant and metal interactions; identification of endocrine disruptive contaminants and their overall ecological significance; and finally, estimating the relative contribution of environmental contamination as a factor affecting wild mammal populations.
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Brun, Nadja Rebecca; Wehrli, Bernhard; Fent, Karl
2016-02-01
Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L(-1) molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L(-1). From OPV, copper (14 μg L(-1)), zinc (87 μg L(-1)) and silver (78 μg L(-1)) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. Copyright © 2015 Elsevier B.V. All rights reserved.
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Dorigo, Ursula; Bourrain, Xavier; Bérard, Annette; Leboulanger, Christophe
2004-01-05
A study was undertaken to investigate the environmental impact of herbicides on natural communities of freshwater periphyton and phytoplankton in the river Ozanne and in related nearby water reservoirs, including both pristine and pesticide- (atrazine and isoproturon) contaminated stations. The microalgal toxicity of both herbicides was investigated by short-term studies, using the in vivo fluorescence pattern to perform dose-effect experiments. The taxonomic composition of the communities sampled was assessed by microscopy and by HPLC pigment analysis. The EC50 (periphyton) or EC125 (phytoplankton) values, calculated using in vivo fluorescence endpoints, increased with the herbicide concentration found in the water. In contrast, the structure of the algal communities (periphyton) inhabiting the contaminated stations seemed to be permanently affected when compared to the reference community. A 'memory effect' could be detected, both in herbicide sensitivity and in the structure of periphytic communities that persisted even when peak contaminations had disappeared. This study shows that the response of algal communities is likely to reflect past selection pressures, and suggests that the function and structure of a community could both be modified by the persistent or repeated presence of microcontaminants in natural environments. We could use short-term ecotoxicological tests on freshwater microalgae to assess the effects of past temporary contaminations by agricultural pesticides, and combining this with diversity indices could make it possible to assess the ecotoxicological risk of herbicide contamination even when a complete chemical analysis of the contamination is not feasible.
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Muñiz, Selene; Gonzalvo, Pilar; Valdehita, Ana; Molina-Molina, José Manuel; Navas, José María; Olea, Nicolás; Fernández-Cascán, Jesús; Navarro, Enrique
2017-11-01
An ecotoxicological survey of soils that were polluted with wastes from lindane (γ-HCH) production assessed the effects of organochlorine compounds on the metabolism of microbial communities and the toxicity of these compounds to a native earthworm (Allolobophora chlorotica). Furthermore, the bioremediation role of earthworms as facilitators of soil washing and the microbial degradation of these organic pollutants were also studied. Soil samples that presented the highest concentrations of ε-HCH, 2,4,6-trichlorophenol, pentachlorobenzene and γ-HCH were extremely toxic to earthworms in the short term, causing the death of almost half of the population. In addition, these soils inhibited the heterotrophic metabolic activity of the microbial community. These highly polluted samples also presented substances that were able to activate cellular detoxification mechanisms (measured as EROD and BFCOD activities), as well as compounds that were able to cause endocrine disruption. A few days of earthworm activity increased the extractability of HCH isomers (e.g., γ-HCH), facilitating the biodegradation of organochlorine compounds and reducing the intensity of endocrine disruption in soils that had low or medium contamination levels. Copyright © 2017 Elsevier Inc. All rights reserved.
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Holden, Patricia A; Gardea-Torresdey, Jorge L; Klaessig, Fred; Turco, Ronald F; Mortimer, Monika; Hund-Rinke, Kerstin; Cohen Hubal, Elaine A; Avery, David; Barceló, Damià; Behra, Renata; Cohen, Yoram; Deydier-Stephan, Laurence; Ferguson, P Lee; Fernandes, Teresa F; Herr Harthorn, Barbara; Henderson, W Matthew; Hoke, Robert A; Hristozov, Danail; Johnston, John M; Kane, Agnes B; Kapustka, Larry; Keller, Arturo A; Lenihan, Hunter S; Lovell, Wess; Murphy, Catherine J; Nisbet, Roger M; Petersen, Elijah J; Salinas, Edward R; Scheringer, Martin; Sharma, Monita; Speed, David E; Sultan, Yasir; Westerhoff, Paul; White, Jason C; Wiesner, Mark R; Wong, Eva M; Xing, Baoshan; Steele Horan, Meghan; Godwin, Hilary A; Nel, André E
2016-06-21
Engineered nanomaterials (ENMs) are increasingly entering the environment with uncertain consequences including potential ecological effects. Various research communities view differently whether ecotoxicological testing of ENMs should be conducted using environmentally relevant concentrations-where observing outcomes is difficult-versus higher ENM doses, where responses are observable. What exposure conditions are typically used in assessing ENM hazards to populations? What conditions are used to test ecosystem-scale hazards? What is known regarding actual ENMs in the environment, via measurements or modeling simulations? How should exposure conditions, ENM transformation, dose, and body burden be used in interpreting biological and computational findings for assessing risks? These questions were addressed in the context of this critical review. As a result, three main recommendations emerged. First, researchers should improve ecotoxicology of ENMs by choosing test end points, duration, and study conditions-including ENM test concentrations-that align with realistic exposure scenarios. Second, testing should proceed via tiers with iterative feedback that informs experiments at other levels of biological organization. Finally, environmental realism in ENM hazard assessments should involve greater coordination among ENM quantitative analysts, exposure modelers, and ecotoxicologists, across government, industry, and academia.
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Si, Wantong; He, Xiaoying; Li, Ailing; Liu, Li; Li, Jisheng; Gong, Donghui; Liu, Juan; Liu, Jumei; Shen, Weishou; Zhang, Xuefeng
2016-09-01
We utilized a multi-biomarker approach (Integrated Biomarker Response version 2, IBRv2) to investigate the scope and dispersion of groundwater contamination surrounding a rare earth mine tailings impoundment. Parameters of SD rat included in our IBRv2 analyses were glutathione levels, superoxide dismutase, catalase, and glutathione peroxidase activities, total anti-oxidative capacity, chromosome aberration, and micronucleus formation. The concentration of 20 pollutants including Cl(-), SO4 (2-), Na(+), K(+), Mg(2+), Ca(2+), TH, CODMn, As, Se, TDS, Be, Mn, Co, Ni, Cu, Zn, Mo, Cd, and Pb in the groundwater were also analyzed. The results of this study indicated that groundwater polluted by tailings impoundment leakage exhibited significant ecotoxicological effects. The selected biomarkers responded sensitively to groundwater pollution. Analyses showed a significant relationship between IBRv2 values and the Nemerow composite index. IBRv2 could serve as a sensitive ecotoxicological diagnosis method for assessing groundwater contamination in the vicinity of rare earth mine tailings. According to the trend of IBRv2 value and Nemerow composite index, the maximum diffusion distance of groundwater pollutants from rare earth mine tailings was approximately 5.7 km.
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Murugadas, Anbazhagan; Zeeshan, Mohammed; Thamaraiselvi, Kaliannan; Ghaskadbi, Surendra; Akbarsha, Mohammad Abdulkader
2016-07-15
Nanotechnology has emerged as a powerful field of applied research. However, the potential toxicity of nano-materials is a cause of concern. A thorough toxicological investigation is required before a nanomaterial is evaluated for application of any kind. In this context, there is concerted effort to find appropriate test systems to assess the toxicity of nanomaterials. Toxicity of a nanomaterial greatly depends on its physicochemical properties and the biological system with which it interacts. The present research was carried out with a view to generate data on eco-toxicological impacts of copper oxide nanorod (CuO NR) in Hydra magnipapillata 105 at organismal, cellular and molecular levels. Exposure of hydra to CuO NR resulted in severe morphological alterations in a concentration- as well as duration-dependent manner. Impairment of feeding, population growth, and regeneration was also observed. In vivo and in vitro analyses revealed induction of oxidative stress, genotoxicity, and molecular machinery of apoptotic cell death, accompanied by disruption of cell cycle progression. Taken together, CuO nanorod is potentially toxic to the biological systems. Also, hydra offers potential to be used as a convenient model organism for aquatic ecotoxicological risk assessment of nanomaterials.
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Murugadas, Anbazhagan; Zeeshan, Mohammed; Thamaraiselvi, Kaliannan; Ghaskadbi, Surendra; Akbarsha, Mohammad Abdulkader
2016-01-01
Nanotechnology has emerged as a powerful field of applied research. However, the potential toxicity of nano-materials is a cause of concern. A thorough toxicological investigation is required before a nanomaterial is evaluated for application of any kind. In this context, there is concerted effort to find appropriate test systems to assess the toxicity of nanomaterials. Toxicity of a nanomaterial greatly depends on its physicochemical properties and the biological system with which it interacts. The present research was carried out with a view to generate data on eco-toxicological impacts of copper oxide nanorod (CuO NR) in Hydra magnipapillata 105 at organismal, cellular and molecular levels. Exposure of hydra to CuO NR resulted in severe morphological alterations in a concentration- as well as duration-dependent manner. Impairment of feeding, population growth, and regeneration was also observed. In vivo and in vitro analyses revealed induction of oxidative stress, genotoxicity, and molecular machinery of apoptotic cell death, accompanied by disruption of cell cycle progression. Taken together, CuO nanorod is potentially toxic to the biological systems. Also, hydra offers potential to be used as a convenient model organism for aquatic ecotoxicological risk assessment of nanomaterials. PMID:27417574
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Hazard of Sulfonamides and Detection Technology Research Progress
NASA Astrophysics Data System (ADS)
Jiang, Jiahui; Wang, Guangyu
2017-12-01
As a kind of widely used antibiotic with typical characteristics, sulfonamides have been greatly applied in clinical medicine for long time. It can’t be effectively treated by pollutant disposal system during pharmaceutical process and utilization and will be discharged into natural environment to be one of the antibiotics with great effect. This kind of substance is difficult to be biodegraded and will be easy to accumulate in the environment, generating huge eco-toxicological effect with significant mutagenicity and teratogenic effect. It is the severe threat for ecological balance, human health and drinking water safety. Its environmental behavior and detection technology attract extensive attention home and abroad.
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Temperature-dependent acute toxicity of methomyl pesticide on larvae of 3 Asian amphibian species.
Lau, Edward Tak Chuen; Karraker, Nancy Elizabeth; Leung, Kenneth Mei Yee
2015-10-01
Relative to other animal taxa, ecotoxicological studies on amphibians are scarce, even though amphibians are experiencing global declines and pollution has been identified as an important threat. Agricultural lands provide important habitats for many amphibians, but often these lands are contaminated with pesticides. The authors determined the acute toxicity, in terms of 96-h median lethal concentrations, of the carbamate pesticide methomyl on larvae of 3 Asian amphibian species, the Asian common toad (Duttaphrynus melanostictus), the brown tree frog (Polypedates megacephalus), and the marbled pygmy frog (Microhyla pulchra), at 5 different temperatures (15 °C, 20 °C, 25 °C, 30 °C, and 35 °C) to examine the relationships between temperature and toxicity. Significant interspecific variation in methomyl sensitivity and 2 distinct patterns of temperature-dependent toxicity were found. Because high proportions of malformation among the surviving tadpoles were observed, a further test was carried out on the tree frog to determine effect concentrations using malformation as the endpoint. Concentrations as low as 1.4% of the corresponding 96-h median lethal concentrations at 25 °C were sufficient to cause malformation in 50% of the test population. As the toxicity of pesticides may be significantly amplified at higher temperatures, temperature effects should not be overlooked in ecotoxicological studies and derivation of safety limits in environmental risk assessment and management. © 2015 SETAC.
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Jho, Eun Hea; Im, Jinwoo; Yang, Kyung; Kim, Young-Jin; Nam, Kyoungphile
2015-01-01
This study was set to investigate the changes in the toxicity of arsenic (As)-contaminated soils after washing with phosphate solutions. The soil samples collected from two locations (A: rice paddy and B: forest land) of a former smelter site were contaminated with a similar level of As. Soil washing (0.5 M phosphate solution for 2 h) removed 24.5% As, on average, in soil from both locations. Regardless of soil washing, Location A soil toxicities, determined using Microtox, were greater than that of Location B and this could be largely attributed to different soil particle size distribution. With soils from both locations, the changes in As chemical forms resulted in either similar or greater toxicities after washing. This emphasizes the importance of considering ecotoxicological aspects, which are likely to differ depending on soil particle size distribution and changes in As chemical forms, in addition to the total concentration based remedial goals, in producing ecotoxicologically-sound soils for reuse. In addition, calcium phosphate used as the washing solution seemed to contribute more on the toxic effects of the washed soils than potassium phosphate and ammonium phosphate. Therefore, it would be more appropriate to use potassium or ammonium phosphate than calcium phosphate for phosphate-aided soil washing of the As-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.
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de Menezes Oliveira, Vanessa Bezerra; de Oliveira Bianchi, Miriam; Espíndola, Evaldo Luiz Gaeta
2017-12-13
Pesticides are widely used in agricultural fields to control plant diseases, weeds, and pests; however, the unforeseeable consequences of releasing these compounds into the soil and their effects on terrestrial invertebrates are matters of grave concern. The aim of the present study was to determine the direct impact of 2 pesticides, KRAFT® 36 EC (an insecticide; a.i. abamectin) and SCORE® (a fungicide; a.i. difenoconazole), on nontarget terrestrial invertebrates. Ecotoxicological tests were performed to evaluate the chronic and acute toxicity of these compounds to a potworm (Enchytraeus crypticus), a collembolan (Folsomia candida), and a mite (Hypoaspis aculeifer). The results showed that, for both pesticides, the collembolan F. candida was the most sensitive species, followed by the enchytraeid E. crypticus and the mite H. aculeifer. Effect concentrations at 50% of organisms' reproduction calculated for F. candida, E. crypticus, and H. aculeifer were 0.06, 2.8, and >32 mg of abamectin/kg dry weight soil and 28.9, 125, and 145.5 mg of difenoconazole/kg dry weight soil, respectively. Environmentally relevant concentrations of both pesticides significantly affected the collembolan species. The existence of a potential risk from abamectin and difenoconazole for soil invertebrates even at recommended doses could be identified. Environ Toxicol Chem 2018;9999:1-6. © 2017 SETAC. © 2017 SETAC.
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Hall, E J
2001-01-01
The possible risk of induced malignancies in astronauts, as a consequence of the radiation environment in space, is a factor of concern for long term missions. Cancer risk estimates for high doses of low LET radiation are available from the epidemiological studies of the A-bomb survivors. Cancer risks at lower doses cannot be detected in epidemiological studies and must be inferred by extrapolation from the high dose risks. The standard setting bodies, such as the ICRP recommend a linear, no-threshold extrapolation of risks from high to low doses, but this is controversial. A study of mechanisms of carcinogenesis may shed some light on the validity of a linear extrapolation. The multi-step nature of carcinogenesis suggests that the role of radiation may be to induce a mutation leading to a mutator phenotype. High energy Fe ions, such as those encountered in space are highly effective in inducing genomic instability. Experiments involving the single particle microbeam have demonstrated a "bystander effect", ie a biological effect in cells not themselves hit, but in close proximity to those that are, as well as the induction of mutations in cells where only the cytoplasm, and not the nucleus, have been traversed by a charged particle. These recent experiments cast doubt on the validity of a simple linear extrapolation, but the data are so far fragmentary and conflicting. More studies are necessary. While mechanistic studies cannot replace epidemiology as a source of quantitative risk estimates, they may shed some light on the shape of the dose response relationship and therefore on the limitations of a linear extrapolation to low doses.
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NASA Technical Reports Server (NTRS)
Hall, E. J.
2001-01-01
The possible risk of induced malignancies in astronauts, as a consequence of the radiation environment in space, is a factor of concern for long term missions. Cancer risk estimates for high doses of low LET radiation are available from the epidemiological studies of the A-bomb survivors. Cancer risks at lower doses cannot be detected in epidemiological studies and must be inferred by extrapolation from the high dose risks. The standard setting bodies, such as the ICRP recommend a linear, no-threshold extrapolation of risks from high to low doses, but this is controversial. A study of mechanisms of carcinogenesis may shed some light on the validity of a linear extrapolation. The multi-step nature of carcinogenesis suggests that the role of radiation may be to induce a mutation leading to a mutator phenotype. High energy Fe ions, such as those encountered in space are highly effective in inducing genomic instability. Experiments involving the single particle microbeam have demonstrated a "bystander effect", ie a biological effect in cells not themselves hit, but in close proximity to those that are, as well as the induction of mutations in cells where only the cytoplasm, and not the nucleus, have been traversed by a charged particle. These recent experiments cast doubt on the validity of a simple linear extrapolation, but the data are so far fragmentary and conflicting. More studies are necessary. While mechanistic studies cannot replace epidemiology as a source of quantitative risk estimates, they may shed some light on the shape of the dose response relationship and therefore on the limitations of a linear extrapolation to low doses.
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Linear prediction data extrapolation superresolution radar imaging
NASA Astrophysics Data System (ADS)
Zhu, Zhaoda; Ye, Zhenru; Wu, Xiaoqing
1993-05-01
Range resolution and cross-range resolution of range-doppler imaging radars are related to the effective bandwidth of transmitted signal and the angle through which the object rotates relatively to the radar line of sight (RLOS) during the coherent processing time, respectively. In this paper, linear prediction data extrapolation discrete Fourier transform (LPDEDFT) superresolution imaging method is investigated for the purpose of surpassing the limitation imposed by the conventional FFT range-doppler processing and improving the resolution capability of range-doppler imaging radar. The LPDEDFT superresolution imaging method, which is conceptually simple, consists of extrapolating observed data beyond the observation windows by means of linear prediction, and then performing the conventional IDFT of the extrapolated data. The live data of a metalized scale model B-52 aircraft mounted on a rotating platform in a microwave anechoic chamber and a flying Boeing-727 aircraft were processed. It is concluded that, compared to the conventional Fourier method, either higher resolution for the same effective bandwidth of transmitted signals and total rotation angle of the object or equal-quality images from smaller bandwidth and total angle may be obtained by LPDEDFT.
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First moments of nucleon generalized parton distributions
Wang, P.; Thomas, A. W.
2010-06-01
We extrapolate the first moments of the generalized parton distributions using heavy baryon chiral perturbation theory. The calculation is based on the one loop level with the finite range regularization. The description of the lattice data is satisfactory, and the extrapolated moments at physical pion mass are consistent with the results obtained with dimensional regularization, although the extrapolation in the momentum transfer to t=0 does show sensitivity to form factor effects, which lie outside the realm of chiral perturbation theory. We discuss the significance of the results in the light of modern experiments as well as QCD inspired models.
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Regier, Nicole; Baerlocher, Loïc; Münsterkötter, Martin; Farinelli, Laurent; Cosio, Claudia
2013-08-06
Toxic metals polluting aquatic ecosystems are taken up by inhabitants and accumulate in the food web, affecting species at all trophic levels. It is therefore important to have good tools to assess the level of risk represented by toxic metals in the environment. Macrophytes are potential organisms for the identification of metal-responsive biomarkers but are still underrepresented in ecotoxicology. In the present study, we used next-generation sequencing to investigate the transcriptomic response of Elodea nuttallii exposed to enhanced concentrations of Hg and Cd. We de novo assembled more than 60 000 contigs, of which we found 170 to be regulated dose-dependently by Hg and 212 by Cd. Functional analysis showed that these genes were notably related to energy and metal homeostasis. Expression analysis using nCounter of a subset of genes showed that the gene expression pattern was able to assess toxic metal exposure in complex environmental samples and was more sensitive than other end points (e.g., bioaccumulation, photosynthesis, etc.). In conclusion, we demonstrate the feasibility of using gene expression signatures for the assessment of environmental contamination, using an organism without previous genetic information. This is of interest to ecotoxicology in a wider sense given the possibility to develop specific and sensitive bioassays.
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The developing framework of marine ecotoxicology: Pollutants as a variable in marine ecosystems?
Luoma, Samuel N.
1996-01-01
Marine ecosystems include a subset in which at least some interrelated geochemical, biochemical, physiological, population and community characteristics are changed by pollutants. Moderate contamination is relatively widespread in coastal and estuarine ecosystems, so the subset of ecosystems with at least some processes affected could be relatively large. Pollutant influences have changed and will probably continue to change on time scales of decades. Biological exposures and dose in such ecosystems are species-specific and determined by how the species is exposed to different environmental media and the geochemistry of individual pollutants within those media. Bioaccumulation models offer significant promise for interpreting such exposures. Biological responses to pollutants need to be more directly linked to exposure and dose. At the level of the individual this might be improved by better understanding relationships between tissue concentrations of pollutants and responses to pollutants. Multi-discipline field and laboratory studies combined with advanced understanding of some basic processes have reduced the ambiguities in interpreting a few physiological/organismic responses to pollutants in nature. Recognition of pollutant-induced patterns in population responses could lead to similar advances. A rational framework for ecotoxicology is developing, but its further advance is dependent upon better integration of ecotoxicology with basic marine ecology and biology.
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Białk-Bielińska, Anna; Matzke, Marianne; Caban, Magda; Stolte, Stefan; Kumirska, Jolanta; Stepnowski, Piotr
2018-03-15
Sulphonamides (SAs) are one of the most commonly used veterinary drugs and therefore their residues are regularly found in the environment. So far scientific attention has mostly been paid to the evaluation of their acute ecotoxicological effects with data on long-term effects for non-target organisms still largely missing. Therefore, the main aim of this study was to evaluate the potential toxicities of five sulphonamides to duckweed (Lemna minor) after prolonged exposure time (14days). To elucidate whether their phytotoxic effects result from potential photodegradation products, the toxicity of standard solutions of selected sulphonamides was also investigated in a standard 7-day test but after irradiation (by keeping them under the test conditions) for the selected time (after 7 and 14days). The ecotoxicological tests were accompanied by chemical analyses to be able to link the observed effects to the concentrations and nature of the exposed compounds. The results showed a shift in the toxicity of SAs: a strong decrease in toxicity for the two most toxic sulphonamides (sulphamethoxazole and sulphadimethoxine) and a slight increase in toxicity for three other SAs (sulphadimidine, sulphathiazole, sulphamerazine) in the prolonged test. However, a decrease in the toxicity and concentration of all the SAs was observed when stock solutions were irradiated prior to the toxicity experiment, which suggests that the observed effects towards L. minor of five SAs in the prolonged test cannot be directly associated with the degradation of these compounds under the test conditions but with their different mode of toxic action towards these organisms. Copyright © 2017 Elsevier B.V. All rights reserved.
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Godoy, Aline A; Kummrow, Fábio; Pamplin, Paulo Augusto Z
2015-07-01
Antihypertensive pharmaceuticals, including the beta-blockers, are one of the most detected therapeutic classes in the environment. The ecotoxicity of propranolol hydrochloride and losartan potassium was evaluated, both individually and combined in a binary mixture, by using the Lemna minor growth inhibition test. The endpoints evaluated in the single-pharmaceutical tests were frond number, total frond area and fresh weight. For the evaluation of the mixture toxicity, the selected endpoint was frond number. Water quality criteria values (WQC) were derived for the protection of freshwater and saltwater pelagic communities regarding the effects induced by propranolol and losartan using ecotoxicological data from the literature, including our data. The risks associated with both pharmaceutical effects on non-target organisms were quantified through the measured environmental concentration (MEC)/predicted-no-effect concentration (PNEC) ratios. For propranolol, the total frond area was the most sensitive endpoint (EC50 = 77.3 mg L(-1)), while for losartan there was no statistically significant difference between the endpoints. Losartan is only slightly more toxic than propranolol. Both concentration addition and independent action models overestimated the mixture toxicity of the pharmaceuticals at all the effect concentration levels evaluated. The joint action of both pharmaceuticals showed an antagonistic interaction to L. minor. Derived WQC assumed lower values for propranolol than for losartan. The MEC/PNEC ratios showed that propranolol may pose a risk for the most sensitive aquatic species, while acceptable risks posed by losartan were estimated for most of aquatic matrices. To the authors knowledge these are the first data about losartan toxicity for L. minor.
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An analysis of the nucleon spectrum from lattice partially-quenched QCD
DOE Office of Scientific and Technical Information (OSTI.GOV)
W. Armour; Allton, C. R.; Leinweber, Derek B.
2010-09-01
The chiral extrapolation of the nucleon mass, Mn, is investigated using data coming from 2-flavour partially-quenched lattice simulations. The leading one-loop corrections to the nucleon mass are derived for partially-quenched QCD. A large sample of lattice results from the CP-PACS Collaboration is analysed, with explicit corrections for finite lattice spacing artifacts. The extrapolation is studied using finite range regularised chiral perturbation theory. The analysis also provides a quantitative estimate of the leading finite volume corrections. It is found that the discretisation, finite-volume and partial quenching effects can all be very well described in this framework, producing an extrapolated value ofmore » Mn in agreement with experiment. This procedure is also compared with extrapolations based on polynomial forms, where the results are less encouraging.« less
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Caetano, Ana Luisa; Marques, Catarina R.; Gavina, Ana; Carvalho, Fernando; Gonçalves, Fernando; da Silva, Eduardo Ferreira; Pereira, Ruth
2014-01-01
In order to regulate the management of contaminated land, many countries have been deriving soil screening values (SSV). However, the ecotoxicological data available for uranium is still insufficient and incapable to generate SSVs for European soils. In this sense, and so as to make up for this shortcoming, a battery of ecotoxicological assays focusing on soil functions and organisms, and a wide range of endpoints was carried out, using a natural soil artificially spiked with uranium. In terrestrial ecotoxicology, it is widely recognized that soils have different properties that can influence the bioavailability and the toxicity of chemicals. In this context, SSVs derived for artificial soils or for other types of natural soils, may lead to unfeasible environmental risk assessment. Hence, the use of natural regional representative soils is of great importance in the derivation of SSVs. A Portuguese natural reference soil PTRS1, from a granitic region, was thereby applied as test substrate. This study allowed the determination of NOEC, LOEC, EC20 and EC50 values for uranium. Dehydrogenase and urease enzymes displayed the lowest values (34.9 and <134.5 mg U Kg, respectively). Eisenia andrei and Enchytraeus crypticus revealed to be more sensitive to uranium than Folsomia candida. EC50 values of 631.00, 518.65 and 851.64 mg U Kg were recorded for the three species, respectively. Concerning plants, only Lactuca sativa was affected by U at concentrations up to 1000 mg U kg1. The outcomes of the study may in part be constrained by physical and chemical characteristics of soils, hence contributing to the discrepancy between the toxicity data generated in this study and that available in the literature. Following the assessment factor method, a predicted no effect concentration (PNEC) value of 15.5 mg kg−1 dw was obtained for U. This PNEC value is proposed as a SSV for soils similar to the PTRS1. PMID:25353962
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Perrodin, Yves; Donguy, Gilles; Bazin, Christine; Volatier, Laurence; Durrieu, Claude; Bony, Sylvie; Devaux, Alain; Abdelghafour, Mohammed; Moretto, Robert
2012-08-01
The dredged sediments of polluted seaports now raise complex management problems since it is no longer possible to discharge them into the sea. This results in the need to manage them on land, raising other types of technical, economic and environmental problems. Regarding the technical and economic dimensions, traditional waste treatment methods have proved to be poorly adapted, due to very high costs and low absorbable volumes. In this context, filling quarries in coastal areas with treated sediments could represent an interesting alternative for these materials. Nevertheless, for the environmental dimension, it is necessary to demonstrate that this possibility is harmless to inland ecosystems. Consequently, a specific ecotoxicological risk assessment methodology has been formulated and tested on three sediments taken from seaboards of France, in view to providing an operational and usable tool for the prior validation of any operation to fill quarries with treated seaport sediments. This method incorporates the formulation of a global conceptual model of the scenario studied and the definition of protocols for each of its steps: the characterisation of exposures (based on a simulation of sediment deposit), the characterisation of effects (via the study of sediments ecotoxicity), and the final ecotoxicological risk assessment performed as a calculation of a risk quotient. It includes the implementation in parallel of two types of complementary approach: the "substances" approach derived from the European methodology for assessing new substances placed on the market, and the "matrix" approach which is similar to methods developed in France to assess ecological risks in other domains (waste management, polluted site management, …). The application of this dual approach to the three sediments tested led to conclude with reliability that the project to deposit sediments "1" and "2" presented a low risk for the peripheral aquatic ecosystems while sediment "3" presented a high risk. Copyright © 2012 Elsevier B.V. All rights reserved.
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Lapa, N; Santos, Oliveira J F; Camacho, S L; Circeo, L J
2002-01-01
Plasma is the fourth state of matter, following the three states of solid, liquid and gas. Experience has amply demonstrated that solids exposed to the oxygen-deficient plasma flame are converted to liquid, and liquid exposed to the same flame is converted to gas. A low amount of vitrified solid residue material usually remains at the end of this process. Plasma pyrolysis/vitrification (PP/V) has been demonstrated as a safe, efficient, cost-effective technology for the treatment of wastes, including hazardous wastes. Besides the low amounts of gaseous byproducts that PP/V produces, the solid vitrified residue presents a low leachability of pollutants. Studies have been performed in many countries in order to assess the leachability of chemical substances. But from the results of identified studies, none has reported results on the ecotoxicological properties of the leachates. The aim of this study was to contribute to the assessment of ecotoxic risk of four different vitrified materials. Vitrified samples of contaminated soils, municipal solid wastes, and incinerator bottom ashes were submitted to the European leaching pre-standard test number prEN 12457-2. The leachates were analyzed for 22 chemical parameters. The biological characterization comprised the assessment of bioluminescence inhibition of Photobacterium phosphoreum bacterium, growth inhibition of Pseudokirchneriella subcapitata algae and the germination inhibition of Lactuca sativa vegetable. The chemical and ecotoxicological results were analyzed according to the French proposal of Criteria on the Evaluation Methods of Waste Toxicity (CEMWT) and a Toxicity Classification System (TCS). The chemical and ecotoxicological results indicated a low leachability of pollutants and a low toxicity level of leachates. All samples studied were as below the TCS class 1 level (no significant toxicity observed) and as non-ecotoxic for CEMWT. Therefore, the environmental ecotoxic risk of the analyzed vitrified samples was determined to be very low.
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AQUATOX Frequently Asked Questions
Capabilities, Installation, Source Code, Example Study Files, Biotic State Variables, Initial Conditions, Loadings, Volume, Sediments, Parameters, Libraries, Ecotoxicology, Waterbodies, Link to Watershed Models, Output, Metals, Troubleshooting
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Low-dose extrapolation model selection for evaluating the health effects of environmental pollutants is a key component of the risk assessment process. At a workshop held in Baltimore, MD, on April 23-24, 2007, and sponsored by U.S. Environmental Protection Agency (EPA) and Johns...
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Wein, G.; Rosier, B.
1998-12-31
This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Wein, G.; Rosier, B.
1997-12-31
This report provides an overview of the research programs and program components carried out by the Savannah River Ecology Laboratory. Research focused on the following: advanced analytical and spectroscopic techniques for developing novel waste isolation and stabilization technologies as well as cost-effective remediation strategies; ecologically sound management of damaged and remediation of ecological systems; ecotoxicology, remediation, and risk assessment; radioecology, including dose assessments for plants and animals exposed to environmental radiation; and other research support programs.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Perko, Z; Bortfeld, T; Hong, T
Purpose: The safe use of radiotherapy requires the knowledge of tolerable organ doses. For experimental fractionation schemes (e.g. hypofractionation) these are typically extrapolated from traditional fractionation schedules using the Biologically Effective Dose (BED) model. This work demonstrates that using the mean dose in the standard BED equation may overestimate tolerances, potentially leading to unsafe treatments. Instead, extrapolation of mean dose tolerances should take the spatial dose distribution into account. Methods: A formula has been derived to extrapolate mean physical dose constraints such that they are mean BED equivalent. This formula constitutes a modified BED equation where the influence of themore » spatial dose distribution is summarized in a single parameter, the dose shape factor. To quantify effects we analyzed 14 liver cancer patients previously treated with proton therapy in 5 or 15 fractions, for whom also photon IMRT plans were available. Results: Our work has two main implications. First, in typical clinical plans the dose distribution can have significant effects. When mean dose tolerances are extrapolated from standard fractionation towards hypofractionation they can be overestimated by 10–15%. Second, the shape difference between photon and proton dose distributions can cause 30–40% differences in mean physical dose for plans having the same mean BED. The combined effect when extrapolating proton doses to mean BED equivalent photon doses in traditional 35 fraction regimens resulted in up to 7–8 Gy higher doses than when applying the standard BED formula. This can potentially lead to unsafe treatments (in 1 of the 14 analyzed plans the liver mean dose was above its 32 Gy tolerance). Conclusion: The shape effect should be accounted for to avoid unsafe overestimation of mean dose tolerances, particularly when estimating constraints for hypofractionated regimens. In addition, tolerances established for a given treatment modality cannot necessarily be applied to other modalities with drastically different dose distributions.« less
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Ecotoxicology of organic contaminants to amphibians
Sparling, D.W.; Sparling, Donald W.; Linder, Greg L.; Bishop, Christine A.
2000-01-01
The effects of organic contaminants on amphibians are poorly known but of considerable interest. These contaminants include the highly toxic dioxins and furans as well as PCBs, PAHs and organochlorine pesticides. Although these compounds may have lower acute toxicity than dioxins and furans, they have been implicated in several problems associated with genotoxicity, endocrine disruption, malformations and reduced growth. There is evidence that amphibian tadpoles bioaccumulate these organic compounds and may have biological concentrating factors ranging in the hundreds. This chapter reviews what is known about the effects and concentrations of organic contaminants in amphibians and provides recommendations for further research
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Temperature extrapolation of multicomponent grand canonical free energy landscapes
NASA Astrophysics Data System (ADS)
Mahynski, Nathan A.; Errington, Jeffrey R.; Shen, Vincent K.
2017-08-01
We derive a method for extrapolating the grand canonical free energy landscape of a multicomponent fluid system from one temperature to another. Previously, we introduced this statistical mechanical framework for the case where kinetic energy contributions to the classical partition function were neglected for simplicity [N. A. Mahynski et al., J. Chem. Phys. 146, 074101 (2017)]. Here, we generalize the derivation to admit these contributions in order to explicitly illustrate the differences that result. Specifically, we show how factoring out kinetic energy effects a priori, in order to consider only the configurational partition function, leads to simpler mathematical expressions that tend to produce more accurate extrapolations than when these effects are included. We demonstrate this by comparing and contrasting these two approaches for the simple cases of an ideal gas and a non-ideal, square-well fluid.
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Uribe-Rivera, David E; Soto-Azat, Claudio; Valenzuela-Sánchez, Andrés; Bizama, Gustavo; Simonetti, Javier A; Pliscoff, Patricio
2017-07-01
Climate change is a major threat to biodiversity; the development of models that reliably predict its effects on species distributions is a priority for conservation biogeography. Two of the main issues for accurate temporal predictions from Species Distribution Models (SDM) are model extrapolation and unrealistic dispersal scenarios. We assessed the consequences of these issues on the accuracy of climate-driven SDM predictions for the dispersal-limited Darwin's frog Rhinoderma darwinii in South America. We calibrated models using historical data (1950-1975) and projected them across 40 yr to predict distribution under current climatic conditions, assessing predictive accuracy through the area under the ROC curve (AUC) and True Skill Statistics (TSS), contrasting binary model predictions against temporal-independent validation data set (i.e., current presences/absences). To assess the effects of incorporating dispersal processes we compared the predictive accuracy of dispersal constrained models with no dispersal limited SDMs; and to assess the effects of model extrapolation on the predictive accuracy of SDMs, we compared this between extrapolated and no extrapolated areas. The incorporation of dispersal processes enhanced predictive accuracy, mainly due to a decrease in the false presence rate of model predictions, which is consistent with discrimination of suitable but inaccessible habitat. This also had consequences on range size changes over time, which is the most used proxy for extinction risk from climate change. The area of current climatic conditions that was absent in the baseline conditions (i.e., extrapolated areas) represents 39% of the study area, leading to a significant decrease in predictive accuracy of model predictions for those areas. Our results highlight (1) incorporating dispersal processes can improve predictive accuracy of temporal transference of SDMs and reduce uncertainties of extinction risk assessments from global change; (2) as geographical areas subjected to novel climates are expected to arise, they must be reported as they show less accurate predictions under future climate scenarios. Consequently, environmental extrapolation and dispersal processes should be explicitly incorporated to report and reduce uncertainties in temporal predictions of SDMs, respectively. Doing so, we expect to improve the reliability of the information we provide for conservation decision makers under future climate change scenarios. © 2017 by the Ecological Society of America.
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Ortiz de García, Sheyla; García-Encina, Pedro A; Irusta-Mata, Rubén
2016-01-01
The presence of pharmaceuticals and personal care products (PPCPs) in the environment has become a real and widespread concern in recent years. Therefore, the primary goal of this study was to investigate 20 common and widely used PPCPs to assess their individual and combined effect on an important species in one trophic level, i.e., bacteria. The ecotoxicological effects of PPCPs at two different concentration ranges were determined in the bacterium Vibrio fischeri using Microtox(®) and were statistically analyzed using three models in the GraphPad Prism 6 program for Windows, v.6.03. A four-parameter model best fit the majority of the compounds. The half maximal effective concentration (EC50) of each PPCP was estimated using the best-fitting model and was compared with the results from a recent study. Comparative analysis indicated that most compounds showed the same level of toxicity. Moreover, the stimulatory effects of PPCPs at environmental concentrations (low doses) were assessed. These results indicated that certain compounds have traditional inverted U- or J-shaped dose-response curves, and 55% of them presented a stimulatory effect below the zero effect-concentration point. Effective concentrations of 0 (EC0), 5 (EC5) and 50% (EC50) were calculated for each PPCP as the ecotoxicological points. All compounds that presented narcosis as a mode of toxic action at high doses also exhibited stimulation at low concentrations. The maximum stimulatory effect of a mixture was higher than the highest stimulatory effect of each individually tested compound. Moreover, when the exposure time was increased, the hormetic effect decreased. Hormesis is being increasingly included in dose-response studies because this may have a harmful, beneficial or indifferent effect in an environment. Despite the results obtained in this research, further investigations need to be conducted to elucidate the behavior of PPCPs in aquatic environments.
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PAH toxicity at aqueous solubility in the fish embryo test with Danio rerio using passive dosing.
Seiler, Thomas-Benjamin; Best, Nina; Fernqvist, Margit Møller; Hercht, Hendrik; Smith, Kilian E C; Braunbeck, Thomas; Mayer, Philipp; Hollert, Henner
2014-10-01
As part of the risk assessment process within REACh, prior to manufacturing and distribution of chemical substances their (eco)toxicological impacts have to be investigated. The fish embryo toxicity test (FET) with the zebrafish Danio rerio has gained a high significance as an in vitro alternative to animal testing in (eco)toxicology. However, for hydrophobic organic chemicals it remains a technical challenge to ensure constant freely dissolved concentration at the maximum exposure level during such biotests. Passive dosing with PDMS silicone was thus applied to control the freely dissolved concentration of ten PAHs at their saturation level in the FET. The experiments gave repeatable results, with the toxicity of the PAHs generally increasing with the maximum chemical activities of the PAHs. HPLC analysis confirmed constant exposure at the saturation level. In additional experiments, fish embryos without direct contact to the silicone surface showed similar mortalities as those exposed with direct contact to the silicone. Silicone oil overlaying the water phase as a novel passive dosing phase had no observable effects on the development of the fish embryos until hatching. This study provides further data to support the close relationship between the chemical activity and the toxicity of hydrophobic organic compounds. Passive dosing from PDMS silicone enabled reliable toxicity testing of (highly) hydrophobic substances at aqueous solubility, providing a practical way to control toxicity exactly at the maximum exposure level. This approach is therefore expected to be useful as a cost-effective initial screening of hydrophobic chemicals for potential adverse effects to freshwater vertebrates. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Tête, Nicolas; Afonso, Eve; Bouguerra, Ghada; Scheifler, Renaud
2015-11-01
Small mammal populations living on contaminated sites are exposed to various chemicals. Lead (Pb) and cadmium (Cd), two well-known nonessential trace metals, accumulate in different organs and are known to cause multiple adverse effects. To develop nonlethal markers in ecotoxicology, the present work aimed to study the relationships between blood parameters (hematocrit, leukocyte levels and granulated erythrocyte levels) and Cd and Pb concentrations in the soil and in the liver and kidneys of wood mice (Apodemus sylvaticus). Individuals were trapped along a pollution gradient with high levels of Cd, Pb and zinc (Zn) contamination. The results indicated that hematological parameters were independent of individual characteristics (age and gender). Blood parameters varied along the pollution gradient, following a pattern similar to the accumulation of Cd in the organs of the wood mice. No relationship was found between the blood parameters studied and Pb concentrations in the organs or in the environment. The hematocrit and leukocyte number decreased with increasing concentrations of Cd in the kidneys and/or in the liver. Moreover, the hematocrit was lower in the animals that were above the thresholds (LOAELs) for Cd concentrations in the liver. These responses were interpreted as a warning of potential negative effects of Cd exposure on the oxygen transport capacity of the blood (e.g., anemia). The present results suggest that blood parameters, notably hematocrit, may offer a minimally invasive biomarker for the evaluation of Cd exposure in further ecotoxicological studies. Copyright © 2014 Elsevier Ltd. All rights reserved.
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NASA Astrophysics Data System (ADS)
Sheikh, M. A.; Higuchi, T.; Imo, T. S.; Fujimura, H.; Oomori, T.
2007-12-01
Spatial and temporal behavior of the tributyl tin (TBT) were investigated in the coastal areas around Okinawa Island, Japan. A seasonal monitoring study was conducted between February and October 2006. The effects of TBT on the carbon metabolisms (net production and calcification) on the intact coral-alga association Galaxea fascicularis were also investigated. Mean concentration of TBT (2.45 ng/L) found in the Manko estuary waters have exceeded some international permissible targets of waters quality guideline for TBT (1ng/L). The sediments in Manko estuary sediments can be considered lightly contaminated (0-20 ng/g dw) and Okukubi estuary as uncontaminated (below 3ng/g dw) with TBT. The seasonal concentration pattern of TBT at the Manko estuary was autumn > spring > summer > winter. The acute ecotoxicological results show that the photosynthesis rate and calcification rate were significantly reduced by 78 % and 72 % relative to the control (ANOVA, p<0.001) when corals were exposed to 5000 ng/LTBT, respectively. No significant effects (ANOVA, p>0.05) were observed when corals were exposed to 1000 ng/LTBT. The present study reports the occurrence and continuous input of TBT in the coastal areas around Okinawa Island, even 16 years after legal restriction of TBT usage in coastal waters was implemented by the Japanese Environmental Authorities. However, the nominal sensitive concentration of TBT that causes alteration of carbon metabolisms of coral within 96 hrs exposure are much higher than those recently found in the coral reef waters and adjacent ecosystems.
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Threatened southern African soils: A need for appropriate ecotoxicological risk assessment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eijsackers, Herman; Reinecke, Adriaan; Reinecke, Sophie
In southern Africa arable soils are limited due to low rainfall and are threatened by anthropogenic activities like agriculture and mining making it susceptible to degradation. The aim of this study is to review the existing information available with regards to soil contamination and its possible threats towards biodiversity and quality of southern African soils. Some of the issues being addressed in this paper include the focus areas of ecotoxicological research in southern African countries, levels of contaminants in soils, the impacts of climate on soil animals and the representativity of standardised test species. In order to address this, wemore » report on a literature search, which was done to determine the main focus areas of soil ecotoxicological research, highlighting strengths and research needs in comparison to approaches elsewhere in the world. Further, to address if the risk assessment approaches of Europe and the USA are valid for southern African environmental conditions; this in the light of differences in temperature, rainfall and fauna. It is concluded that risk assessment procedures for Europe and the USA were based on non-southern African conditions making it necessary to rethink risk assessment studies; although limited, in southern Africa. We recommend future research that has to be undertaken to address these issues. This research should include investigating species sensitivities in responses to contamination and including insects likes ants and termites in ecological risk assessment studies.« less
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Ecotoxicological criteria for final storage quality: Possibilities and limits
NASA Astrophysics Data System (ADS)
Zeyer, Josef; Meyer, Joseph
Landfills are complex chemical and biological reactors whose internal processes are often beyond the immediate control of process engineers. Therefore, the concept of a "Final Storage Landfill" may be deceptive. Furthermore, traditional approaches to establishing discharge criteria and treatment requirements for industrial effluents may not work well for landfill emissions. Factories can often be treated as steady-state processes whose inputs and outputs are predictable; however, landfills are batch reactors whose contents and emissions may be unknown and will vary temporally and spatially. If the contents of a landfill are known, the sequence of chemical reactions can be predicted qualitatively. Even if that sequence is predictable, though, quantitative ecotoxicological criteria will be difficult to establish, and risk assessments based on chemical "laundry lists" will be questionable. The situation is not hopeless, though. New approaches can be developed to monitor and predict landfill emissions. We believe these will include (1) testing (biological and chemical) of internal components of landfills as well as emissions; (2) development of laboratory and/or field methods in which the chemical and biological evolution of landfills can be studied at accelerated rates, thus allowing better prediction of future emissions; and (3) flexible ecotoxicological criteria that are adaptable to the evolving nature of landfill emissions. These criteria should be based on complementary chemical analyses and biological tests that fit into a hierarchical (decision-tree) hazard assessment strategy.
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Tigini, Valeria; Prigione, Valeria; Varese, Giovanna Cristina
2014-07-15
Pollution caused by landfill leachates is one of the main problems of urbanised areas, on account of their chemical composition, which turn in an ineffective treatment. A characterisation of leachates, which takes into account chemical, ecotoxicological and mycological aspects, is basilar for the evaluation of environmental impact of leachate and the development of suitable treatment techniques. In this study, the toxicity of a raw leachate and an effluent coming from traditional wastewater treatment plant was assessed by means of 4 ecotoxicological assays. Both the samples exceed the legal threshold value according to all the tested organisms, indicating the ineffectiveness of activated sludge treatment in the reduction of toxicity. The autochthonous mycoflora of the two samples was evaluated by filtration. The fungal load was 73 CFU for leachate and 102 CFU for the effluent. Ascomycetes were the dominant fraction (81% and 61%, for leachate and effluent respectively), followed by basidiomycetes (19% and 39%, respectively). Most of them were potential emerging pathogens. A decolourisation screening with autochthonous fungi was set up towards both samples in the presence or absence of glucose. Eleven fungi (basidiomycetes and ascomycetes) achieved up to 38% decolourisation yields, showing to be promising fungi for the bioremediation of leachates. Further experiment will be aimed to the study of decolourisation mechanism and toxicity reduction. Copyright © 2014 Elsevier B.V. All rights reserved.
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Application of a framework for extrapolating chemical effects ...
Cross-species extrapolation of toxicity data from limited surrogate test organisms to all wildlife with potential of chemical exposure remains a key challenge in ecological risk assessment. A number of factors affect extrapolation, including the chemical exposure, pharmacokinetics, life-stage, and pathway similarities/differences. Here we propose a framework using a tiered approach for species extrapolation that enables a transparent weight-of-evidence driven evaluation of pathway conservation (or lack thereof) in the context of adverse outcome pathways. Adverse outcome pathways describe the linkages from a molecular initiating event, defined as the chemical-biomolecule interaction, through subsequent key events leading to an adverse outcome of regulatory concern (e.g., mortality, reproductive dysfunction). Tier 1 of the extrapolation framework employs in silico evaluations of sequence and structural conservation of molecules (e.g., receptors, enzymes) associated with molecular initiating events or upstream key events. Such evaluations make use of available empirical and sequence data to assess taxonomic relevance. Tier 2 uses in vitro bioassays, such as enzyme inhibition/activation, competitive receptor binding, and transcriptional activation assays to explore functional conservation of pathways across taxa. Finally, Tier 3 provides a comparative analysis of in vivo responses between species utilizing well-established model organisms to assess departure from
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Atomization Energies of SO and SO2; Basis Set Extrapolation Revisted
NASA Technical Reports Server (NTRS)
Bauschlicher, Charles W., Jr.; Ricca, Alessandra; Arnold, James (Technical Monitor)
1998-01-01
The addition of tight functions to sulphur and extrapolation to the complete basis set limit are required to obtain accurate atomization energies. Six different extrapolation procedures are tried. The best atomization energies come from the series of basis sets that yield the most consistent results for all extrapolation techniques. In the variable alpha approach, alpha values larger than 4.5 or smaller than 3, appear to suggest that the extrapolation may not be reliable. It does not appear possible to determine a reliable basis set series using only the triple and quadruple zeta based sets. The scalar relativistic effects reduce the atomization of SO and SO2 by 0.34 and 0.81 kcal/mol, respectively, and clearly must be accounted for if a highly accurate atomization energy is to be computed. The magnitude of the core-valence (CV) contribution to the atomization is affected by missing diffuse valence functions. The CV contribution is much more stable if basis set superposition errors are accounted for. A similar study of SF, SF(+), and SF6 shows that the best family of basis sets varies with the nature of the S bonding.
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Properties of infrared extrapolations in a harmonic oscillator basis
Coon, Sidney A.; Kruse, Michael K. G.
2016-02-22
Here, the success and utility of effective field theory (EFT) in explaining the structure and reactions of few-nucleon systems has prompted the initiation of EFT-inspired extrapolations to larger model spaces in ab initio methods such as the no-core shell model (NCSM). In this contribution, we review and continue our studies of infrared (ir) and ultraviolet (uv) regulators of NCSM calculations in which the input is phenomenological NN and NNN interactions fitted to data. We extend our previous findings that an extrapolation in the ir cutoff with the uv cutoff above the intrinsic uv scale of the interaction is quite successful,more » not only for the eigenstates of the Hamiltonian but also for expectation values of operators, such as r 2, considered long range. The latter results are obtained with Hamiltonians transformed by the similarity renormalization group (SRG) evolution. On the other hand, a possible extrapolation of ground state energies in the uv cutoff when the ir cutoff is below the intrinsic ir scale is not robust and does not agree with the ir extrapolation of the same data or with independent calculations using other methods.« less
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Aparecida Maranho, Lucineide; Teresinha Maranho, Leila; Grossi Botelho, Rafael; Luiz Tornisielo, Valdemar
2014-09-29
The aim of this one-year study (August 2009 to July 2010) was to evaluate the Corumbataí River water polluted by anthropogenic sources and see how it affects the reproduction of the microcrustacean Ceriodaphnia dubia (Richard, 1984) in laboratory conditions over seven days of exposure to water samples collected monthly at six different locations. We determined the concentrations of zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), and cadmium (Cd), as well as physicochemical parameters such as dissolved oxygen, conductivity, water temperature, and pH. Dissolved oxygen and conductivity demonstrated anthropogenic influence, as dissolved oxygen concentration decreased and conductivity increased from the upstream to the downstream stretch of the river. The effects on C. dubia were observed in the months with high precipitation, but the toxicity cannot be associated with any particular contaminant. Heavy metal levels kept well below the limit values. Zn and Pb had the highest concentrations in the water during the sampling period, probably due to the industrial and agricultural influence. However, these levels do not seem to be associated with precipitation, which suggests that their primary source was industry. Physicochemical parameters, the ecotoxicological assay, and determination of heavy metals proved to be efficient tools to evaluate aquatic environments.
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Lucchetti, Roberta; Siciliano, Antonietta; Clarizia, Laura; Russo, Danilo; Di Somma, Ilaria; Di Natale, Francesco; Guida, Marco; Andreozzi, Roberto; Marotta, Raffaele
2017-02-01
The photocatalytic removal of nitrate with simultaneous hydrogen generation was demonstrated using zero-valent nano-copper-modified titania (P25) as photocatalyst in the presence of UV-A-Vis radiation. Glycerol, a by-product in biodiesel production, was chosen as a hole scavenger. Under the adopted experimental conditions, a nitrate removal efficiency up to 100% and a simultaneous hydrogen production up to 14 μmol/L of H 2 were achieved (catalyst load = 150 mg/L, initial concentration of nitrate = 50 mg/L, initial concentration of glycerol = 0.8 mol/L). The reaction rates were independent of the starting glycerol concentration. This process allows accomplishing nitrate removal, with the additional benefit of producing hydrogen under artificial UV-A radiation. A kinetic model was also developed and it may represent a benchmark for a detailed understanding of the process kinetics. A set of acute and chronic bioassays (Vibrio fischeri, Raphidocelis subcapitata, and Daphnia magna) was performed to evaluate the potential ecotoxicity of the nitrate/by-product mixture formed during the photocatalytic process. The ecotoxicological assessment indicated an ecotoxic effect of oxidation intermediates and by-products produced during the process.
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Haegerbaeumer, Arne; Höss, Sebastian; Ristau, Kai; Claus, Evelyn; Möhlenkamp, Christel; Heininger, Peter; Traunspurger, Walter
2016-12-01
Soft sediments are often hotspots of chemical contamination, and a thorough ecotoxicological assessment of this habitat can help to identify the causes of stress and to improve the health of the respective ecosystems. As an important component of the ecologically relevant meiobenthic fauna, nematodes can be used for sediment assessments, with various assay tools ranging from single-species toxicity tests to field studies. In the present study, microcosms containing sediment were used to investigate direct and indirect effects of zinc on natural nematode assemblages, and acute community toxicity tests considering only direct toxicity were conducted. The responses of the various freshwater nematode species in both approaches were compared with those of Caenorhabditis elegans, determined in standardized tests (ISO 10872). At a median lethal concentration (LC50) of 20 mg Zn/L, C. elegans represented the median susceptibility of 15 examined nematode species examined in the acute community toxicity tests. In the microcosms, Zn affected the nematodes dose-dependently, with changes in species composition first detected at 13 mg Zn/kg to 19 mg Zn/kg sediment dry weight. The observed species sensitivities in the microcosms corresponded better to field observations than to the results of the acute community toxicity tests. Environ Toxicol Chem 2016;35:2987-2997. © 2016 SETAC. © 2016 SETAC.
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Compliance of LC50 and NOEC data with Benford's Law: an indication of reliability?
de Vries, Pepijn; Murk, Albertinka J
2013-12-01
Reliability of research data is essential, especially when potentially far-reaching conclusions will be based on them. This is also, amongst others, the case for ecotoxicological data used in risk assessment. Currently, several approaches are available to classify the reliability of ecotoxicological data. The process of classification, such as using the Klimisch score, is time-consuming and focuses on the application of standardised protocols and the documentation of the study. The presence of irregularities and the integrity of the performed work, however, are not addressed. The present study shows that Benford's Law, based on the occurrence of first digits following a logarithmic scale, can be applied to ecotoxicity test data for identifying irregularities. This approach is already successfully applied in accounting. Benford's Law can be used as reliability indicator, in addition to existing reliability classifications. The law can be used to efficiently trace irregularities in large data sets of interpolated (no) effect concentrations such as LC50s (possibly the result of data manipulation), without having to evaluate the source of each individual record. Application of the law to systems in which large amounts of toxicity data are registered (e.g., European Commission Regulation concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals) can therefore be valuable. © 2013 Elsevier Inc. All rights reserved.
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Adeleye, Adedayo O; Jin, Haiyan; Di, Yanan; Li, Donghao; Chen, Jianfang; Ye, Ying
2016-01-15
A wide variety of persistent organic pollutants (POPs) in the surface marine sediments and seafood from four geographic areas of the East China Sea were investigated. The POP concentrations were analyzed and their possible ecotoxicological risks assessed. The total concentrations of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) in the sediments were found to be ND-22.40, ND-5.10, 32.10-171.70, and 0.60-63.00 ng/g dry weight (dw), respectively. Low-chlorinated biphenyl congeners and HCHs were predominantly found at the Hangzhou Bay and Yangtze River areas. The sediment ecotoxicological risk was assessed, indicating the toxic effect of PCBs and DDTs on benthic organisms. In marine organisms of economic importance, the concentration of total PAHs, PCBs, and organochlorine pesticides (OCPs) ranged from 43.20 to 291.20, 2.60 to 96.20, and 12.70 to 235.20 μg/kg dw, respectively. The bioaccumulation in marine organisms did not pose a significant health risk to consumers. As indicated by the POP residues in both marine sediments and organisms, POPs were persistent over time, posing a long-term risk to the local ecosystem and human health via the food chain. Copyright © 2015 Elsevier B.V. All rights reserved.
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Chen, Wei-Yu; Jou, Li-John; Chen, Suz-Hsin; Liao, Chung-Min
2012-05-01
Arsenic (As) is the element of greatest ecotoxicological concern in aquatic environments. Effective monitoring and diagnosis of As pollution via a biological early warning system is a great challenge for As-affected regions. The purpose of this study was to synthesize water chemistry-based bioavailability and valve daily rhythm in Corbicula fluminea to design a biomonitoring system for detecting waterborne As. We integrated valve daily rhythm dynamic patterns and water chemistry-based Hill dose-response model to build into a programmatic mechanism of inductance-based valvometry technique for providing a rapid and cost-effective dynamic detection system. A LabVIEW graphic control program in a personal computer was employed to demonstrate completely the functional presentation of the present dynamic system. We verified the simulated dissolved As concentrations based on the valve daily rhythm behavior with published experimental data. Generally, the performance of this proposed biomonitoring system demonstrates fairly good applicability to detect waterborne As concentrations when the field As concentrations are less than 1 mg L(-1). We also revealed that the detection times were dependent on As exposure concentrations. This biomonitoring system could particularly provide real-time transmitted information on the waterborne As activity under various aquatic environments. This parsimonious C. fluminea valve rhythm behavior-based real-time biomonitoring system presents a valuable effort to promote the automated biomonitoring and offers early warnings on potential ecotoxicological risks in regions with elevated As exposure concentrations.
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Overview of ecotoxicological studies performed in the Venice Lagoon (Italy).
Losso, C; Ghirardini, A Volpi
2010-01-01
This work reports on the state of the art of the bioindicators used to assess environmental quality (regarding chemical pollutant impacts) in the Venice lagoon. After a brief description of the roles, advantages and limitations of bioindicators in marine and transitional environments and a summary of the Venice lagoon characteristics, the ecotoxicological methods used during scientific studies and research projects in the Lagoon are reported. Since not all data are available and no database can be formulated, the main evidence from toxicity bioassays, biomarkers and bioaccumulation analyses since the end of the 1970s is spatially synthesized using maps and discussed according to the four Venice lagoon basins. The majority of indicators showed that the Lido basin (north-central lagoon), affected by the presence of the industrial area and the city of Venice, is the one most highly impacted (particularly in the sites located within or in front of the industrial area, which showed very high sediment toxicity and high levels of DNA damage). The Malamocco basin (south-central lagoon) seems to be the least problematic. The southern basin (Chioggia basin) was shown to be impacted by urban contaminants from the town of Chioggia. The northern basin (Treporti basin) presented both impacted sites (high toxicity and high bioaccumulation factor) and relatively unpolluted sites (absence of toxicity, absence of imposex and low levels of bioaccumulation). This review can serve as a basis on which to select pragmatic, cost-effective biomonitoring techniques for environmental effects in lagoon ecosystems.
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Quinn, Brian; Gagné, Francois; Weber, Jean-Philippe; Blaise, Christian
2005-01-01
A biomarker study was undertaken using the Calico scallop Argopecten gibbus to assess the ecotoxicological effects of a semi-submerged municipal dump on the adjacent patch reef lagoon ecosystem (Castle harbour, Bermuda). Caged scallops were deployed in situ for 2 months at various distances from the dump (50 m, 900 m and 2.7 km) and at a reference site (14 km). A suite of biomarkers comprising metallothionein (MT), lipid peroxidation (LPO), vitellin-like proteins (Vn), glutathione S-transferase (GST), DNA strand breaks and condition factor (CF) were investigated in various tissues of the scallop (gill, digestive gland and gonad). Levels of heavy metals were also measured in the whole scallop soft tissue. While there was some variation in response between tissues, in general the results indicated that the dump was negatively impacting scallops deployed in the adjacent marine environment: elevated levels of MT, DNA strand breaks, Vn and GST and reduced condition factor were found for scallops deployed nearest to the dump and at the site 1.5 km from this point source of contamination (Tuckers town) in Castle harbour, with respect to the reference site, North Rock (although this exhibited some degree of metal contamination). The gills from scallops deployed at the dump site were the most responsive tissue, with the highest expression of MT, LPO and DNA damage. This study indicates the potential of the Calico scallop as a convenient bioindicator species in the marine tropical benthos.
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Application of the backward extrapolation method to pulsed neutron sources
DOE Office of Scientific and Technical Information (OSTI.GOV)
Talamo, Alberto; Gohar, Yousry
We report particle detectors operated in pulse mode are subjected to the dead-time effect. When the average of the detector counts is constant over time, correcting for the dead-time effect is simple and can be accomplished by analytical formulas. However, when the average of the detector counts changes over time it is more difficult to take into account the dead-time effect. When a subcritical nuclear assembly is driven by a pulsed neutron source, simple analytical formulas cannot be applied to the measured detector counts to correct for the dead-time effect because of the sharp change of the detector counts overmore » time. This work addresses this issue by using the backward extrapolation method. The latter can be applied not only to a continuous (e.g. californium) external neutron source but also to a pulsed external neutron source (e.g. by a particle accelerator) driving a subcritical nuclear assembly. Finally, the backward extrapolation method allows to obtain from the measured detector counts both the dead-time value and the real detector counts.« less
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Application of the backward extrapolation method to pulsed neutron sources
Talamo, Alberto; Gohar, Yousry
2017-09-23
We report particle detectors operated in pulse mode are subjected to the dead-time effect. When the average of the detector counts is constant over time, correcting for the dead-time effect is simple and can be accomplished by analytical formulas. However, when the average of the detector counts changes over time it is more difficult to take into account the dead-time effect. When a subcritical nuclear assembly is driven by a pulsed neutron source, simple analytical formulas cannot be applied to the measured detector counts to correct for the dead-time effect because of the sharp change of the detector counts overmore » time. This work addresses this issue by using the backward extrapolation method. The latter can be applied not only to a continuous (e.g. californium) external neutron source but also to a pulsed external neutron source (e.g. by a particle accelerator) driving a subcritical nuclear assembly. Finally, the backward extrapolation method allows to obtain from the measured detector counts both the dead-time value and the real detector counts.« less
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Manfra, Loredana; Canepa, Sara; Piazza, Veronica; Faimali, Marco
2016-01-01
Swimming speed alteration and mortality assays with the marine crustacean Artemia franciscana were carried out. EC50 and LC50 values after 24-48h exposures were calculated for two reference toxicants, copper sulphate pentahydrate (CuSO4·5H2O) and Sodium Dodecyl Sulphate (SDS), and an ecotoxicological concern organic compound, Diethylene Glycol (DEG). Different end-points have been evaluated, in order to point out their sensitivity levels. The swimming speed alteration (SSA) was compared to mortality values and also to the hatching rate inhibition (literature data). SSA resulted to be more sensitive than the mortality and with a sensitivity comparable to (or even higher than) the hatching rate endpoint. Copyright © 2015 Elsevier Inc. All rights reserved.
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Oliveira-Filho, Eduardo C; Brito, Darlan Q; Dias, Zelia M B; Guarieiro, Mayara S; Carvalho, Esther L; Fascineli, Maria L; Niva, Cintia C; Grisolia, Cesar K
2018-03-15
Wildfire is very common in Brazilian savannas, and its effects on water, soil and aquatic/soil organisms are poorly understood. In this study, we observed the effects of fire, especially of ashes, on surface soil and subsurface water in a typical Brazilian savanna (Cerrado sensu strictu) for one year. Soil analyses (pH, organic matter content, potential acidity, K, Ca, Mg and P) and subsurface water analyses (NO 3- , PO 4 3- Mg 2+ , Ca 2+ and K + ) were assessed. We evaluated the ecotoxicological effects of ashes on three different endpoints and species, in fish Danio rerio (embryonic development), aquatic snail Biomphalaria glabrata (reproduction) and a soil species Enchytraeus sp. (reproduction). We found a higher amount of exchangeable cations and organic matter content in short-term fire effects on soil, but the higher availability of nutrients did not affect the soil pH in field plots. The effects of ashes on soil and subsurface water did not persist for one-year post-fire, except for organic matter content in burned areas. No toxic effects were observed on hatching success and incidences of developmental abnormalities in D. rerio embryos. However, ash input had adverse effects on reproduction in snails and enchytraeids. We reported a statistically significant decrease in snail eggs exposed to the 50g.L -1 and 100g.L -1 of ashes after four weeks (p<0.05, Dunnett's test and Tukey test). Enchytraeus sp. reproduction was negatively influenced by the natural soil, which presents high acidity, and also when exposed directly to the ashes from burned area, suggesting that pH and other ash compounds may limit the growth of enchytraeids. More studies in burned areas are strongly encouraged, addressing the potential important routes of exposure to ashes in order to understand the impact of intense fires on soil and aquatic biota in tropical savannas. Copyright © 2017 Elsevier B.V. All rights reserved.
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ECOTOXICOLOGY OF NANOMATERIALS
An overview of issues associated with potential ecological toxicity of nanomaterials with research needs outlined, current literature reviewed and discussion of nanomaterial toxicity relative to concerns that EPA and state risk assessors might have.
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Larsen, Ross E.
2016-04-12
In this study, we introduce two simple tight-binding models, which we call fragment frontier orbital extrapolations (FFOE), to extrapolate important electronic properties to the polymer limit using electronic structure calculations on only a few small oligomers. In particular, we demonstrate by comparison to explicit density functional theory calculations that for long oligomers the energies of the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and of the first electronic excited state are accurately described as a function of number of repeat units by a simple effective Hamiltonian parameterized from electronic structure calculations on monomers, dimers and, optionally,more » tetramers. For the alternating copolymer materials that currently comprise some of the most efficient polymer organic photovoltaic devices one can use these simple but rigorous models to extrapolate computed properties to the polymer limit based on calculations on a small number of low-molecular-weight oligomers.« less
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Ecotoxicology of mercury in fish and wildlife: Recent advances
Scheuhammer, Anton M.; Basu, Niladri; Evers, David C.; Heinz, Gary H.; Sandheinrich, Mark B.; Bank, Michael S.; edited by Bank, Michael S.; Bank, Michael S.
2012-01-01
A number of recent studies have documented subtle, yet potentially important effects of mercury on behavior, neurochemistry, and endocrine function in fish and wildlife at currently realistic levels of environmental exposure. Current levels of environmental methylmercury exposure are sufficient to cause significant biological impairment, both in individuals and in whole populations, in some ecosystems. Future toxicological studies on fish and wildlife will focus on linking biomarkers of methylmercury exposure and associated oxidative stress to effects on reproduction and population change; determining the genetic basis for mercury-related neurotoxic and other biological changes; determining the genetic basis for species differences in sensitivity to methylmercury; and linking toxic effects of methylmercury in individual animals to population-level changes.
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Surface dose measurements with commonly used detectors: a consistent thickness correction method.
Reynolds, Tatsiana A; Higgins, Patrick
2015-09-08
The purpose of this study was to review application of a consistent correction method for the solid state detectors, such as thermoluminescent dosimeters (chips (cTLD) and powder (pTLD)), optically stimulated detectors (both closed (OSL) and open (eOSL)), and radiochromic (EBT2) and radiographic (EDR2) films. In addition, to compare measured surface dose using an extrapolation ionization chamber (PTW 30-360) with other parallel plate chambers RMI-449 (Attix), Capintec PS-033, PTW 30-329 (Markus) and Memorial. Measurements of surface dose for 6MV photons with parallel plate chambers were used to establish a baseline. cTLD, OSLs, EDR2, and EBT2 measurements were corrected using a method which involved irradiation of three dosimeter stacks, followed by linear extrapolation of individual dosimeter measurements to zero thickness. We determined the magnitude of correction for each detector and compared our results against an alternative correction method based on effective thickness. All uncorrected surface dose measurements exhibited overresponse, compared with the extrapolation chamber data, except for the Attix chamber. The closest match was obtained with the Attix chamber (-0.1%), followed by pTLD (0.5%), Capintec (4.5%), Memorial (7.3%), Markus (10%), cTLD (11.8%), eOSL (12.8%), EBT2 (14%), EDR2 (14.8%), and OSL (26%). Application of published ionization chamber corrections brought all the parallel plate results to within 1% of the extrapolation chamber. The extrapolation method corrected all solid-state detector results to within 2% of baseline, except the OSLs. Extrapolation of dose using a simple three-detector stack has been demonstrated to provide thickness corrections for cTLD, eOSLs, EBT2, and EDR2 which can then be used for surface dose measurements. Standard OSLs are not recommended for surface dose measurement. The effective thickness method suffers from the subjectivity inherent in the inclusion of measured percentage depth-dose curves and is not recommended for these types of measurements.
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Embryotoxicity of lead on Bufo arenarum
DOE Office of Scientific and Technical Information (OSTI.GOV)
Perez-Coll, C.S.; Herkovits, J.; Salibian, A.
1988-08-01
Lead, one of the oldest and more widely distributed pollutants, produces serious toxicological effects. From an ecotoxicological point of view, amphibians are useful as indicators of environmental contamination because they are sensitive to a great variety of toxic agents. Considering that Bufo arenarum is one of the most widely distributed toads in South America, in the present work the authors study the LC50 and teratogenical effects of lead on Bufo arenarum embryos obtained from different couples of parents exposing them from the 2-cell stage onwards. A differential susceptibility to this heavy metal in embryos obtained from five different couples ofmore » parents is described.« less
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2006-07-01
linearity; (4) determination of polarization as a function of radiographic parameters ; and (5) determination of the effect of binding energy on... hydroxyapatite . Type II calcifications are known to be associated with carcinoma, while it is generally accepted that the exclusive finding of type I...concentrate on the extrapolation of the Rh target spectra. The extrapolation was split in two parts. Below 24 keV we used the parameters from Boone’s paper
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The database provides chemical-specific toxicity information for aquatic life, terrestrial plants, and terrestrial wildlife. ECOTOX is a comprehensive ecotoxicology database and is therefore essential for providing and suppoirting high quality models needed to estimate population...
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Challenges of accelerated aging techniques for elastomer lifetime predictions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gillen, Kenneth T.; Bernstein, R.; Celina, M.
Elastomers are often degraded when exposed to air or high humidity for extended times (years to decades). Lifetime estimates normally involve extrapolating accelerated aging results made at higher than ambient environments. Several potential problems associated with such studies are reviewed, and experimental and theoretical methods to address them are provided. The importance of verifying time–temperature superposition of degradation data is emphasized as evidence that the overall nature of the degradation process remains unchanged versus acceleration temperature. The confounding effects that occur when diffusion-limited oxidation (DLO) contributes under accelerated conditions are described, and it is shown that the DLO magnitude canmore » be modeled by measurements or estimates of the oxygen permeability coefficient (P Ox) and oxygen consumption rate (Φ). P Ox and Φ measurements can be influenced by DLO, and it is demonstrated how confident values can be derived. In addition, several experimental profiling techniques that screen for DLO effects are discussed. Values of Φ taken from high temperature to temperatures approaching ambient can be used to more confidently extrapolate accelerated aging results for air-aged materials, and many studies now show that Arrhenius extrapolations bend to lower activation energies as aging temperatures are lowered. Furthermore, best approaches for accelerated aging extrapolations of humidity-exposed materials are also offered.« less
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Lorenz, Alyson; Dhingra, Radhika; Chang, Howard H; Bisanzio, Donal; Liu, Yang; Remais, Justin V
2014-01-01
Extrapolating landscape regression models for use in assessing vector-borne disease risk and other applications requires thoughtful evaluation of fundamental model choice issues. To examine implications of such choices, an analysis was conducted to explore the extent to which disparate landscape models agree in their epidemiological and entomological risk predictions when extrapolated to new regions. Agreement between six literature-drawn landscape models was examined by comparing predicted county-level distributions of either Lyme disease or Ixodes scapularis vector using Spearman ranked correlation. AUC analyses and multinomial logistic regression were used to assess the ability of these extrapolated landscape models to predict observed national data. Three models based on measures of vegetation, habitat patch characteristics, and herbaceous landcover emerged as effective predictors of observed disease and vector distribution. An ensemble model containing these three models improved precision and predictive ability over individual models. A priori assessment of qualitative model characteristics effectively identified models that subsequently emerged as better predictors in quantitative analysis. Both a methodology for quantitative model comparison and a checklist for qualitative assessment of candidate models for extrapolation are provided; both tools aim to improve collaboration between those producing models and those interested in applying them to new areas and research questions.
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Challenges of accelerated aging techniques for elastomer lifetime predictions
Gillen, Kenneth T.; Bernstein, R.; Celina, M.
2015-03-01
Elastomers are often degraded when exposed to air or high humidity for extended times (years to decades). Lifetime estimates normally involve extrapolating accelerated aging results made at higher than ambient environments. Several potential problems associated with such studies are reviewed, and experimental and theoretical methods to address them are provided. The importance of verifying time–temperature superposition of degradation data is emphasized as evidence that the overall nature of the degradation process remains unchanged versus acceleration temperature. The confounding effects that occur when diffusion-limited oxidation (DLO) contributes under accelerated conditions are described, and it is shown that the DLO magnitude canmore » be modeled by measurements or estimates of the oxygen permeability coefficient (P Ox) and oxygen consumption rate (Φ). P Ox and Φ measurements can be influenced by DLO, and it is demonstrated how confident values can be derived. In addition, several experimental profiling techniques that screen for DLO effects are discussed. Values of Φ taken from high temperature to temperatures approaching ambient can be used to more confidently extrapolate accelerated aging results for air-aged materials, and many studies now show that Arrhenius extrapolations bend to lower activation energies as aging temperatures are lowered. Furthermore, best approaches for accelerated aging extrapolations of humidity-exposed materials are also offered.« less
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How Accurate Are Infrared Luminosities from Monochromatic Photometric Extrapolation?
NASA Astrophysics Data System (ADS)
Lin, Zesen; Fang, Guanwen; Kong, Xu
2016-12-01
Template-based extrapolations from only one photometric band can be a cost-effective method to estimate the total infrared (IR) luminosities ({L}{IR}) of galaxies. By utilizing multi-wavelength data that covers across 0.35-500 μm in GOODS-North and GOODS-South fields, we investigate the accuracy of this monochromatic extrapolated {L}{IR} based on three IR spectral energy distribution (SED) templates out to z˜ 3.5. We find that the Chary & Elbaz template provides the best estimate of {L}{IR} in Herschel/Photodetector Array Camera and Spectrometer (PACS) bands, while the Dale & Helou template performs best in Herschel/Spectral and Photometric Imaging Receiver (SPIRE) bands. To estimate {L}{IR}, we suggest that extrapolations from the available longest wavelength PACS band based on the Chary & Elbaz template can be a good estimator. Moreover, if the PACS measurement is unavailable, extrapolations from SPIRE observations but based on the Dale & Helou template can also provide a statistically unbiased estimate for galaxies at z≲ 2. The emission with a rest-frame 10-100 μm range of IR SED can be well described by all three templates, but only the Dale & Helou template shows a nearly unbiased estimate of the emission of the rest-frame submillimeter part.
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The ECOTOXicology Knowledgebase (ECOTOX), is a comprehensive, curated database that summarizes toxicology data fromsingle chemical exposure studies to aquatic life, terrestrial plants, and wildlife. The ECOTOX Knowledgebase currently has curated data from over 47,000 references a...
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Papadakis, Emmaluel N; Vryzas, Zisis; Kotopoulou, Athena; Kintzikoglou, Katerina; Makris, Konstantinos C; Papadopoulou-Mourkidou, Euphemia
2015-06-01
A pesticide monitoring study covering the main rivers and lakes of Northern Greece (Macedonia, Thrace and Thessaly) was undertaken. A total of 416 samples were collected over a 1.5-year sampling period (September 1999- February 2001) from six rivers and ten lakes. The water samples were analyzed with an off-line solid phase extraction technique coupled with a gas chromatography ion trap mass spectrometer using an analytical method for 147 pesticides and their metabolites, including organochlorines, organophosphates, triazines, chloroacetanilides, pyrethroids, carbamates, phthalimides and other pesticides (herbicides, insecticides and fungicides). Based on the pesticide survey results, a human health carcinogenic and non-carcinogenic risk assessment was conducted for adults and children. Ecotoxicological risk assessment was also conducted using default endpoint values and the risk quotient method. Results showed that the herbicides metolachlor, prometryn, alachlor and molinate, were the most frequently detected pesticides (29%, 12.5%, 12.5% and 10%, respectively). They also exhibited the highest concentration values, often exceeding 1 μg/L. Chlorpyrifos ethyl was the most frequently detected insecticide (7%). Seasonal variations in measured pesticide concentrations were observed in all rivers and lakes. The highest concentrations were recorded during May-June period, right after pesticide application. Concentrations of six pesticides were above the maximum allowable limit of 0.1 μg/L set for drinking water. Alachlor, atrazine and a-HCH showed unacceptable carcinogenic risk estimates (4.5E-06, 4.6E-06 and 1.3E-04, respectively). Annual average concentrations of chlorpyriphos ethyl (0.031 μg L), dicofol (0.01 μg/L), dieldrin (0.02 μg/L) and endosulfan a (0.065 μg/L) exceeded the EU environmental quality standards. The risk quotient estimates for the insecticides chorpyrifos ethyl, diazinon and parathion methyl and herbicide prometryn were above acceptable risk values. The coupling of monitoring data to probabilistic human and ecotoxicological risk estimates could find use by Greek regulatory authorities, proposing effective pollution management schemes. Copyright © 2015 Elsevier Inc. All rights reserved.
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Santorufo, Lucia; Van Gestel, Cornelis A M; Maisto, Giulia
2012-07-01
This study aimed at assessing the quality of urban soils by integrating chemical and ecotoxicological approaches. Soils from five sites in downtown Naples, Italy, were sampled and characterized for physical-chemical properties and total and water-extractable metal concentrations. Bioassays with Eisenia andrei, Enchytraeus crypticus and Folsomia candida were performed to assess toxicity of the soils, using survival, reproduction and growth as the endpoints. Metal bioaccumulation in the animals was also measured. The properties and metal concentrations of the soils strongly differed. Metal bioaccumulation was related with total metal concentrations in soil and was highest in E. crypticus, which was more sensitive than E. andrei and F. candida. Responses of the three species to the investigated soils seemed due to both metal contamination and soil properties. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Robidoux, P Y; Choucri, A; Bastien, C; Sunahara, G I; López-Gastey, J
2001-01-01
Septic tank sludge is regularly hauled to the Montreal Urban Community (MUC) wastewater treatment plant. It is then discharged and mixed with the wastewater inflow before entering the primary chemical treatment process. An ecotoxicological procedure integrating chemical and toxicological analyses has been recently developed and applied to screen for the illicit discharge of toxic substances in septic sludge. The toxicity tests used were the Microtox, the bacterial-respiration, and the lettuce (Lactuca sativa) root elongation tests. In order to validate the applicability of the proposed procedure, a two-year interlaboratory study was carried out. In general, the results obtained by two independent laboratories (MUC and the Centre d'expertise en analyse environnementale du Quebec) were comparable and reproducible. Some differences were found using the Microtox test. Organic (e.g., phenol and formaldehyde) and inorganic (e.g., nickel and cyanide) spiked septic sludge were detected with good reliability and high efficiency. The relative efficiency to detect spiked substances was > 70% and confirms the results of previous studies. In addition, the respiration test was the most efficient toxicological tool to detect spiked substances, whereas the Microtox was the least efficient (< 15%). Efficiencies to detect spiked contaminants were also similar for both laboratories. These results support previous data presented earlier and contribute to the validation of the ecotoxicological procedure used by the MUC to screen toxicity in septic sludge.
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Advancing the 3Rs in regulatory ecotoxicology: A pragmatic cross-sector approach.
Burden, Natalie; Benstead, Rachel; Clook, Mark; Doyle, Ian; Edwards, Peter; Maynard, Samuel K; Ryder, Kathryn; Sheahan, Dave; Whale, Graham; van Egmond, Roger; Wheeler, James R; Hutchinson, Thomas H
2016-07-01
The ecotoxicity testing of chemicals for prospective environmental safety assessment is an area in which a high number of vertebrates are used across a variety of industry sectors. Refining, reducing, and replacing the use of animals such as fish, birds, and amphibians for this purpose addresses the ethical concerns and the increasing legislative requirements to consider alternative test methods. Members of the UK-based National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) Ecotoxicology Working Group, consisting of representatives from academia, government organizations, and industry, have worked together over the past 6 y to provide evidence bases to support and advance the application of the 3Rs in regulatory ecotoxicity testing. The group recently held a workshop to identify the areas of testing, demands, and drivers that will have an impact on the future of animal use in regulatory ecotoxicology. As a result of these discussions, we have developed a pragmatic approach to prioritize and realistically address key opportunity areas, to enable progress toward the vision of a reduced reliance on the use of animals in this area of testing. This paper summarizes the findings of this exercise and proposes a pragmatic strategy toward our key long-term goals-the incorporation of reliable alternatives to whole-organism testing into regulations and guidance, and a culture shift toward reduced reliance on vertebrate toxicity testing in routine environmental safety assessment. Integr Environ Assess Manag 2016;12:417-421. © 2015 SETAC. © 2015 SETAC.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Overton, J.H.; Jarabek, A.M.
1989-01-01
The U.S. EPA advocates the assessment of health-effects data and calculation of inhaled reference doses as benchmark values for gauging systemic toxicity to inhaled gases. The assessment often requires an inter- or intra-species dose extrapolation from no observed adverse effect level (NOAEL) exposure concentrations in animals to human equivalent NOAEL exposure concentrations. To achieve this, a dosimetric extrapolation procedure was developed based on the form or type of equations that describe the uptake and disposition of inhaled volatile organic compounds (VOCs) in physiologically-based pharmacokinetic (PB-PK) models. The procedure assumes allometric scaling of most physiological parameters and that the value ofmore » the time-integrated human arterial-blood concentration must be limited to no more than to that of experimental animals. The scaling assumption replaces the need for most parameter values and allows the derivation of a simple formula for dose extrapolation of VOCs that gives equivalent or more-conservative exposure concentrations values than those that would be obtained using a PB-PK model in which scaling was assumed.« less
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Oláh, Viktor; Hepp, Anna; Mészáros, Ilona
2015-08-01
Standard ecotoxicological test procedures use only active forms of aquatic plants. The potential effects of toxicants on vegetative propagules, which play an important role in the survival of several aquatic plant species, is not well understood. Because turion-like resting propagules overwinter on the water bottom in temperate regions, they could be exposed to contaminants for longer periods than active plants. Due to its turion producing capability, giant duckweed (Spirodela polyrhiza) is widely used in studying morphogenesis, dormancy, and activation mechanisms in plants. It is also suitable for ecotoxicological purposes. The present work aims to compare the growth inhibition sensitivity of active (normal frond) and overwintering (turion) forms of S. polyrhiza to concentrations of nickel (Ni), cadmium (Cd) and hexavalent chromium (Cr) ranging from 0 to 100mgL(-1). The results indicated that in general, resting turions have higher heavy metal tolerance than active fronds. Cd proved to be the most toxic heavy metal to S. polyrhiza active frond cultures because it induced rapid turion formation. In contrast, the toxicity of Ni and Cr were found to be similar but lower than the effects of Cd. Cr treatments up to 10mgL(-1) did not result in any future negative effects on turion activation. Turions did not survive heavy metal treatments at higher concentrations of Cr. Cd and Ni treatments affected both the floating-up and germination of turions but did not significantly affect the vigor of sprouts. Higher concentrations (of 100mgL(-1)) Cd completely inhibited germination. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Manríquez, Patricio H; Llanos-Rivera, Alejandra; Galaz, Sylvana; Camaño, Andrés
2013-12-01
The Chilean abalone or "loco" (Concholepas concholepas, Bruguière 1789) represent the most economically important marine recourse exploited from inner inshore Management and Exploitation Areas for Benthic Resources along the Chilean coast. In this study, newly-hatched larvae of C. concholepas were investigated as a potential model species for marine ecotoxicological studies. The study developed a behavioral standard protocol for assessing the impact that kraft pulp mill effluents after secondary treatment have on C. concholepas larvae. Under controlled laboratory conditions, newly-hatched larvae were exposed to a series of different concentrations of kraft pulp mill effluents with secondary treatment (Pinus spp. and Eucalyptus spp.), potassium dichromate as standard reference toxicant and effluent-free control conditions. Regardless of the type of effluent the results indicated that diluted kraft pulp effluent with secondary treatment had reduced effect on larval survival. Low larval survivals were only recorded when they were exposed to high concentrations of the reference toxicant. This suggests that C. concholepas larval bioassay is a simple method for monitoring the effects of kraft pulp mill effluents with secondary treatment discharged into the sea. The results indicated that dilution of ca. 1% of the effluent with an elemental chlorine free (ECF) secondary treatment is appropriate for achieving low larval mortalities, such as those obtained under control conditions with filtered seawater, and to minimize their impact on early ontogenetic stages of marine invertebrates such as newly-hatched larvae of C. concholepas. The methodological aspects of toxicological testing and behavioral responses described here with newly-hatched larvae of C. concholepas can be used to evaluate in the future the potential effects of other stressful conditions as other pollutants or changes in seawater pH associated with ocean acidification. © 2013 Elsevier Inc. All rights reserved.
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Laitano, R F; Toni, M P; Pimpinella, M; Bovi, M
2002-07-21
The factor Kwall to correct for photon attenuation and scatter in the wall of ionization chambers for 60Co air-kerma measurement has been traditionally determined by a procedure based on a linear extrapolation of the chamber current to zero wall thickness. Monte Carlo calculations by Rogers and Bielajew (1990 Phys. Med. Biol. 35 1065-78) provided evidence, mostly for chambers of cylindrical and spherical geometry, of appreciable deviations between the calculated values of Kwall and those obtained by the traditional extrapolation procedure. In the present work an experimental method other than the traditional extrapolation procedure was used to determine the Kwall factor. In this method the dependence of the ionization current in a cylindrical chamber was analysed as a function of an effective wall thickness in place of the physical (radial) wall thickness traditionally considered in this type of measurement. To this end the chamber wall was ideally divided into distinct regions and for each region an effective thickness to which the chamber current correlates was determined. A Monte Carlo calculation of attenuation and scatter effects in the different regions of the chamber wall was also made to compare calculation to measurement results. The Kwall values experimentally determined in this work agree within 0.2% with the Monte Carlo calculation. The agreement between these independent methods and the appreciable deviation (up to about 1%) between the results of both these methods and those obtained by the traditional extrapolation procedure support the conclusion that the two independent methods providing comparable results are correct and the traditional extrapolation procedure is likely to be wrong. The numerical results of the present study refer to a cylindrical cavity chamber like that adopted as the Italian national air-kerma standard at INMRI-ENEA (Italy). The method used in this study applies, however, to any other chamber of the same type.
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Computer program for pulsed thermocouples with corrections for radiation effects
NASA Technical Reports Server (NTRS)
Will, H. A.
1981-01-01
A pulsed thermocouple was used for measuring gas temperatures above the melting point of common thermocouples. This was done by allowing the thermocouple to heat until it approaches its melting point and then turning on the protective cooling gas. This method required a computer to extrapolate the thermocouple data to the higher gas temperatures. A method that includes the effect of radiation in the extrapolation is described. Computations of gas temperature are provided, along with the estimate of the final thermocouple wire temperature. Results from tests on high temperature combustor research rigs are presented.
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Vlčková, Klára; Hofman, Jakub
2012-01-01
The close relationship between soil organic matter and the bioavailability of POPs in soils suggests the possibility of using it for the extrapolation between different soils. The aim of this study was to prove that TOC content is not a single factor affecting the bioavailability of POPs and that TOC based extrapolation might be incorrect, especially when comparing natural and artificial soils. Three natural soils with increasing TOC and three artificial soils with TOC comparable to these natural soils were spiked with phenanthrene, pyrene, lindane, p,p'-DDT, and PCB 153 and studied after 0, 14, 28, and 56 days. At each sampling point, total soil concentration and bioaccumulation in earthworms Eisenia fetida were measured. The results showed different behavior and bioavailability of POPs in natural and artificial soils and apparent effects of aging on these differences. Hence, direct TOC based extrapolation between various soils seems to be limited. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Line-of-sight extrapolation noise in dust polarization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Poh, Jason; Dodelson, Scott
The B-modes of polarization at frequencies ranging from 50-1000 GHz are produced by Galactic dust, lensing of primordial E-modes in the cosmic microwave background (CMB) by intervening large scale structure, and possibly by primordial B-modes in the CMB imprinted by gravitational waves produced during inflation. The conventional method used to separate the dust component of the signal is to assume that the signal at high frequencies (e.g., 350 GHz) is due solely to dust and then extrapolate the signal down to lower frequency (e.g., 150 GHz) using the measured scaling of the polarized dust signal amplitude with frequency. For typicalmore » Galactic thermal dust temperatures of about 20K, these frequencies are not fully in the Rayleigh-Jeans limit. Therefore, deviations in the dust cloud temperatures from cloud to cloud will lead to different scaling factors for clouds of different temperatures. Hence, when multiple clouds of different temperatures and polarization angles contribute to the integrated line-of-sight polarization signal, the relative contribution of individual clouds to the integrated signal can change between frequencies. This can cause the integrated signal to be decorrelated in both amplitude and direction when extrapolating in frequency. Here we carry out a Monte Carlo analysis on the impact of this line-of-sight extrapolation noise, enabling us to quantify its effect. Using results from the Planck experiment, we find that this effect is small, more than an order of magnitude smaller than the current uncertainties. However, line-of-sight extrapolation noise may be a significant source of uncertainty in future low-noise primordial B-mode experiments. Scaling from Planck results, we find that accounting for this uncertainty becomes potentially important when experiments are sensitive to primordial B-mode signals with amplitude r < 0.0015 .« less
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Ecotoxicological analysis during the removal of carbofuran in fungal bioaugmented matrices.
Ruíz-Hidalgo, Karla; Masís-Mora, Mario; Barbieri, Edison; Carazo-Rojas, Elizabeth; Rodríguez-Rodríguez, Carlos E
2016-02-01
Biomixtures are used for the removal of pesticides from agricultural wastewater. As biomixtures employ high content of lignocellulosic substrates, their bioaugmentation with ligninolytic fungi represents a novel approach for their enhancement. Nonetheless, the decrease in the concentration of the pesticide may result in sublethal concentrations that still affect ecosystems. Two matrices, a microcosm of rice husk (lignocellulosic substrate) bioaugmented with the fungus Trametes versicolor and a biomixture that contained fungally colonized rice husk were used in the degradation of the insecticide/nematicide carbofuran (CFN). Elutriates simulating lixiviates from these matrices were used to assay the ecotoxicological effects at sublethal level over Daphnia magna (Straus) and the fish Oreochromis aureus (Steindachner) and Oncorhynchus mykiss (Walbaum). Elutriates obtained after 30 d of treatment in the rice husk microcosms at dilutions over 2.5% increased the offspring of D. magna as a trade-off stress response, and produced mortality of neonates at dilutions over 5%. Elutriates (dilution 1:200) obtained during a 30 d period did not produce alterations on the oxygen consumption and ammonium excretion of O. mykiss, however these physiological parameters were affected in O. aureus at every time point of treatment, irrespective of the decrease in CFN concentration. When the fungally colonized rice husk was used to prepare a biomixture, where more accelerated degradation is expected, similar alterations on the responses by O. aureus were achieved. Results suggest that despite the good removal of the pesticide, it is necessary to optimize biomixtures to minimize their residual toxicity and potential chronic effects on aquatic life. Copyright © 2015 Elsevier Ltd. All rights reserved.
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D'Adamo, Raffaele; Specchiulli, Antonietta; Cassin, Daniele; Botter, Margherita; Zonta, Roberto; Fabbrocini, Adele
2014-10-01
The effects on the microtidal lagoon of Lesina of runoff and the discharge of water and material from agricultural activities were investigated combining chemical analyses of pollutants [11 metals and 16 priority polycyclic aromatic compounds (PAHs)], determination of organic matter and grain size, and performance of innovative ecotoxicological tests. For metals, enrichment factors >3 for arsenic, nickel, and copper (Cu) were observed in the eastern zone of the lagoon, which is affected by nearby urban activities with discharge of water and domestic waste and by agricultural input with waters rich in fertilizers. Cu was correlated with no other metal, and its high concentrations (≤77 µg g(-1)) may result from the use of Cu-based fungicides in vineyards. Total PAHs (2,230 ± 3,150 ng g(-1)) displayed a wide range of concentrations with hot spots near freshwater inputs from the part of the catchment area exploited for wheat crops. Pyrolitic contamination also emerged, with higher-mass PAH congeners, such as asphalt, bitumen or coal, usually present in higher fractions as the dominant components. Ecotoxicological evaluations recorded moderate to high toxicity levels; the innovative MOT test bioassay showed good discriminatory ability because it identified a lagoon area whose inputs mainly depend on agricultural activities and which is impacted by metals rather than PAHs. Floods during periods of heavy rain and the discharge of water and material from agricultural activities may impact vulnerable systems, such as the lagoon of Lesina, where the presence of hot spots with remarkably high pollution values was observed.
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Rattner, B.A.; Pearson, J.L.; Golden, N.H.; Cohen, J.B.; Erwin, R.M.; Ottinger, M.A.
2000-01-01
In order to examine the condition of biota in Atlantic coast estuaries, a ?Contaminant Exposure and Effects--Terrestrial Vertebrates? database (CEE-TV) has been compiled through computerized search of published literature, review of existing databases, and solicitation of unpublished reports from conservation agencies, private groups, and universities. Summary information has been entered into the database, including species, collection date (1965-present), site coordinates, estuary name, hydrologic unit catalogue code, sample matrix, contaminant concentrations, biomarker and bioindicator responses, and reference source, utilizing a 98-field character and numeric format. Currently, the CEE-TV database contains 3699 georeferenced records representing 190 vertebrate species and >145,000 individuals residing in estuaries from Maine through Florida. This relational database can be directly queried, imported into a Geographic Information System to examine spatial patterns, identify data gaps and areas of concern, generate hypotheses, and focus ecotoxicological field assessments. Information on birds made up the vast majority (83%) of the database, with only a modicum of data on amphibians (75,000 chemical compounds in commerce, only 118 commonly measured environmental contaminants were quantified in tissues of terrestrial vertebrates. There were no CEE-TV data records in 15 of the 67 estuaries located along the Atlantic coast and Florida Gulf coast. The CEE-TV database has a number of potential applications including focusing biomonitoring efforts to generate critically needed ecotoxicological data in the numerous ?gaps? along the coast, reducing uncertainty about contaminant risk, identifying areas for mitigation, restoration or special management, and ranking ecological conditions of estuaries.
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Vaj, Claudia; Barmaz, Stefania; Sørensen, Peter Borgen; Spurgeon, David; Vighi, Marco
2011-11-01
Mixture toxicity is a real world problem and as such requires risk assessment solutions that can be applied within different geographic regions, across different spatial scales and in situations where the quantity of data available for the assessment varies. Moreover, the need for site specific procedures for assessing ecotoxicological risk for non-target species in non-target ecosystems also has to be recognised. The work presented in the paper addresses the real world effects of pesticide mixtures on natural communities. Initially, the location of risk hotspots is theoretically estimated through exposure modelling and the use of available toxicity data to predict potential community effects. The concept of Concentration Addition (CA) is applied to describe responses resulting from exposure of multiple pesticides The developed and refined exposure models are georeferenced (GIS-based) and include environmental and physico-chemical parameters, and site specific information on pesticide usage and land use. As a test of the risk assessment framework, the procedures have been applied on a suitable study areas, notably the River Meolo basin (Northern Italy), a catchment characterised by intensive agriculture, as well as comparative area for some assessments. Within the studied areas, the risks for individual chemicals and complex mixtures have been assessed on aquatic and terrestrial aboveground and belowground communities. Results from ecological surveys have been used to validate these risk assessment model predictions. Value and limitation of the approaches are described and the possibilities for larger scale applications in risk assessment are also discussed. Copyright © 2011 Elsevier Inc. All rights reserved.
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Development of an acute toxicity test with the tropical marine amphipod Parhyale hawaiensis.
Artal, Mariana Coletty; Dos Santos, Amanda; Henry, Theodore Burdick; Umbuzeiro, Gisela de Aragão
2018-03-01
There is a lack of suitable tropical marine species for ecotoxicity tests. An attractive model organism for ecotoxicology is the marine amphipod Parhyale hawaiensis, which is already a model for genetic and developmental studies. This species is widespread, can tolerate changes in salinity, is easy to handle and is representative of circumtropical regions. The aim of this work was to describe standardized procedures for laboratory husbandry, define conditions for acute toxicity tests, and to provide acute toxicity test results for some reference toxicants. Culturing conditions for the organism in the laboratory were established in reconstituted seawater (30 ± 2 salinity), 24 ± 2 °C, photoperiod 12/12 h light/dark. Acute toxicity test procedures were developed for 96 h-exposure time, and organisms at ages <7 days. The miniaturized version of the test, based on 96-well microplates and 200 µL of exposure media provided consistent results compared to larger exposure volumes (80-mL vials protocol). Acute toxicity of Ag, Cd, Cu, Zn and ammonia determined for P. hawaiensis were consistent to previous results for other marine amphipods. We conclude that P. hawaiensis can be successfully cultured in standardized conditions and be effectively used in acute toxicity testing. Further development and use of this model will enable standardized and reproducible ecotoxicology investigations in understudied and vulnerable tropical marine ecosystems.
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[Effect of Environmental Factors on the Ecotoxicity of Pharmaceuticals and Personal Care Products].
Sugihara, Kazumi
2018-01-01
In recent years, pharmaceuticals and personal care products (PPCPs) have emerged as significant pollutants of aquatic environments and have been detected at levels in the range of ng/L to μg/L. The source of PPCPs is humans and livestock that have been administered pharmaceuticals and subsequently excreted them via urine and feces. Unlike agricultural chemicals, the environmental dynamics of PPCPs is not examined and they would undergo structural transformation by environmental factors, e.g., sunlight, microorganisms and treatments in sewage treatment plants (STPs). Processing at STPs can remove various PPCPs; however, they are not removed completely and some persist in the effluents. In this study, we examined the degradation of 9 pharmaceuticals (acetaminophen, amiodarone, dapsone, dexamethasone, indomethacin, raloxifene, phenytoin, naproxen, and sulindac) by sunlight or UV, and investigated the ecotoxicological variation of degradation products. Sunlight (UVA and UVB) degraded most pharmaceuticals, except acetaminophen and phenytoin. Similar results were obtained with UVB and UVA. All the pharmaceuticals were photodegraded by UVC, which is used for sterilization in STPs. Ecotoxicity assay using the luminescent bacteria test (ISO11348) indicated that UVC irradiation increased the toxicity of acetaminophen and phenytoin significantly. The photodegraded product of acetaminophen was identified as 1-(2-amino-5-hydroxyphenyl)ethanone and that of phenytoin as benzophenone, and the authentic compounds showed high toxicity. Photodegraded products of PPCPs are a concern in ecotoxicology.
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Ecotoxicological impact of Zequanox®, a novel biocide, on selected non-target Irish aquatic species.
Meehan, Sara; Shannon, Adam; Gruber, Bridget; Rackl, Sarahann M; Lucy, Frances E
2014-09-01
Effective, species-specific zebra mussel control is needed urgently for Ireland׳s freshwater bodies, which became infested with non-native zebra mussels in the 1990s. Zequanox®, a newly commercialized product for zebra and quagga mussel control, is composed of dead Pseudomonas fluorescens CL 145A cells. This paper describes ecotoxicology tests on three representative native Irish freshwater species: Anodonta (duck mussel), Chironomus plumosus (non-biting midge), and Austropotamobius pallipes (white-clawed crayfish). The species were exposed to Zequanox in a 72-h static renewal toxicity test at concentrations of 100-750mg active ingredient per liter (mga.i./L). Water quality parameters were measured every 12-24h before and after water and product renewal. After 72h, endpoints were reported as LC10, LC50, and LC100. The LC50 values derived were (1) Anodonta: ≥500mga.i./L (2) C. plumosus: 1075mga.i./L, and (3) A. pallipes: ≥750mga.i./L. These results demonstrate that Zequanox does not negatively affect these organisms at the concentration required for >80percent zebra mussel mortality (150mg a.i/L) and the maximum allowable treatment concentration in the United Sates (200mga.i./L). They also show the overall species-specificity of Zequanox, and support its use in commercial facilities and open waters. Copyright © 2014 Elsevier Inc. All rights reserved.
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Guo, Jiahua; Sinclair, Chris J; Selby, Katherine; Boxall, Alistair B A
2016-06-01
Approximately 1500 active pharmaceutical ingredients are currently in use; however, the environmental occurrence and impacts of only a small proportion of these have been investigated. Recognizing that it would be impractical to monitor and assess all pharmaceuticals that are in use, several previous studies have proposed the use of prioritization approaches to identify substances of most concern so that resources can be focused on these. All of these previous approaches suffer from limitations. In the present study, the authors draw on experience from previous prioritization exercises and present a holistic approach for prioritizing pharmaceuticals in the environment in terms of risks to aquatic and soil organisms, avian and mammalian wildlife, and humans. The approach considers both apical ecotoxicological endpoints as well as potential nonapical effects related to the therapeutic mode of action. Application of the approach is illustrated for 146 active pharmaceuticals that are used either in the community or in hospital settings in the United Kingdom. Using the approach, 16 compounds were identified as a potential priority. These substances include compounds belonging to the antibiotic, antidepressant, anti-inflammatory, antidiabetic, antiobesity, and estrogen classes as well as associated metabolites. In the future, the prioritization approach should be applied more broadly around the different regions of the world. Environ Toxicol Chem 2016;35:1550-1559. © 2016 SETAC. © 2016 SETAC.
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Selck, Henriette; Handy, Richard D.; Fernandes, Teresa F.; Klaine, Stephen J.; Petersen, Elijah J.
2016-01-01
The US-EU Community of Research (CoR) was established in 2012 to provide a platform for scientists to develop a ‘shared repertoire of protocols and methods to overcome nanotechnology environmental health and safety (nanoEHS) research gaps and barriers’ (www.us-eu.org/). Based on work within the Ecotoxicology CoR (2012–2015) we provide here an overview of the state-of-the-art of nanomaterials (NMs) in the aquatic environment by addressing different research questions with a focus on ecotoxicological test systems and the challenges faced when assessing nanomaterial (NM) hazards (e.g., uptake routes, bioaccumulation, toxicity, test protocols and model organisms). Our recommendation is to place particular importance on studying the ecological effects of aged/weathered NMs, as-manufactured NMs, as well as NMs released from consumer products in addressing the following overarching research topics: i) NM characterization and quantification in environmental and biological matrices, ii) NM transformation in the environment and consequences for bioavailability and toxicity, iii) alternative methods to assess exposure, iv) influence of exposure scenarios on bioavailability and toxicity, v) development of more environmentally realistic bioassays and vi) uptake, internal distribution, and depuration of NMs. Research addressing these key topics will reduce uncertainty in ecological risk assessment and support the sustainable development of nanotechnology. PMID:27089437
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Ecotoxicological evaluation of three deicers (NaCl, NaFo, CMA)-effect on terrestrial organisms.
Robidoux, P Y; Delisle, C E
2001-02-01
The use of chemical deicers such as sodium chloride (NaCl) has increased significantly during the past three decades. Deicers induce metal corrosion and alter the physicochemical properties of soils and water. Environmental damage caused by the use of NaCl has prompted government agencies to find alternative deicers. This article presents a comparative ecotoxicological study of three deicers on soil organisms. Sodium formiate (NaFo) and calcium-magnesium acetate (CMA) are the most interesting commercially available deicers based upon their characteristics and potential toxicity. Organisms used in this study were four species of macrophytes (cress (Lepidium sativum), barley (Ordeum vulgare), red fescue grass (Festuca rubra), Kentucky bluegrass (Poa pratensis)) and an invertebrate (Eisenia fetida). Using standardized and modified methods, the relative toxicity of deicers was CMA < NaFo congruent with NaCl. The results demonstrate that these chemicals could have similar impacts in terrestrial environments since similar quantities of NaFo and greater amounts of CMA are necessary to achieve the same efficiency as NaCl. The toxicity of the tested substances was lower in natural composted soil than in artificial substrate (silica or OECD soil), indicating decreased environmental bioavailability. The response of the organisms changed according to endpoint, species, and soil characteristics (artificial substrate as compared to natural organic soil). The most sensitive endpoint measured was macrophyte growth with Kentucky bluegrass being the most sensitive species. Copyright 2001 Academic Press.
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A short-term swimming speed alteration test with nauplii of Artemia franciscana.
Morgana, Silvia; Estévez-Calvar, Noelia; Gambardella, Chiara; Faimali, Marco; Garaventa, Francesca
2018-01-01
The presence of toxicant needs to be assessed within short time in order to effectively protect the aquatic environment from serious threat. Based on the observation that at high temperatures aquatic organisms become more vulnerable to stressors than those maintained at room temperature, a new test was developed. The proposed bioassay consisted in the evaluation of the swimming speed alteration (SSA) of nauplii of Artemia franciscana incubated at 39°C (± 1) for 6h, using a Swimming Behavior Recorder system (SBR). A comparative ecotoxicological study between the 6h SSA test and the 24h mortality test was carried out in order to validate the new method in terms of sensitivity by means of EC 50 values. The bioassay was applied to screen different toxicants: K 2 Cr 2 O 7 , Cu(SO 4 ) 2 , NaClO, SDS and Sertraline hydrochloride. The EC 50s calculated for the short-term SSA test and those of the mortality test showed comparable values. For all toxicants, the 6h SSA test was proved to be as sensitive as the 24h mortality test. The method developed in this study is the first temperature-based toxicity test with nauplii of Artemia franciscana and it represents an attractive assay in ecotoxicology because of its convenience in terms of time and costs, feasibility and sensitivity. Copyright © 2017 Elsevier Inc. All rights reserved.
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Hartmann, Nanna B; Jensen, Keld Alstrup; Baun, Anders; Rasmussen, Kirsten; Rauscher, Hubert; Tantra, Ratna; Cupi, Denisa; Gilliland, Douglas; Pianella, Francesca; Riego Sintes, Juan M
2015-01-01
Selecting appropriate ways of bringing engineered nanoparticles (ENP) into aqueous dispersion is a main obstacle for testing, and thus for understanding and evaluating, their potential adverse effects to the environment and human health. Using different methods to prepare (stock) dispersions of the same ENP may be a source of variation in the toxicity measured. Harmonization and standardization of dispersion methods applied in mammalian and ecotoxicity testing are needed to ensure a comparable data quality and to minimize test artifacts produced by modifications of ENP during the dispersion preparation process. Such harmonization and standardization will also enhance comparability among tests, labs, and studies on different types of ENP. The scope of this review was to critically discuss the essential parameters in dispersion protocols for ENP. The parameters are identified from individual scientific studies and from consensus reached in larger scale research projects and international organizations. A step-wise approach is proposed to develop tailored dispersion protocols for ecotoxicological and mammalian toxicological testing of ENP. The recommendations of this analysis may serve as a guide to researchers, companies, and regulators when selecting, developing, and evaluating the appropriateness of dispersion methods applied in mammalian and ecotoxicity testing. However, additional experimentation is needed to further document the protocol parameters and investigate to what extent different stock dispersion methods affect ecotoxicological and mammalian toxicological responses of ENP.
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The design of L1-norm visco-acoustic wavefield extrapolators
NASA Astrophysics Data System (ADS)
Salam, Syed Abdul; Mousa, Wail A.
2018-04-01
Explicit depth frequency-space (f - x) prestack imaging is an attractive mechanism for seismic imaging. To date, the main focus of this method was data migration assuming an acoustic medium, but until now very little work assumed visco-acoustic media. Real seismic data usually suffer from attenuation and dispersion effects. To compensate for attenuation in a visco-acoustic medium, new operators are required. We propose using the L1-norm minimization technique to design visco-acoustic f - x extrapolators. To show the accuracy and compensation of the operators, prestack depth migration is performed on the challenging Marmousi model for both acoustic and visco-acoustic datasets. The final migrated images show that the proposed L1-norm extrapolation results in practically stable and improved resolution of the images.
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Review of Air Vitiation Effects on Scramjet Ignition and Flameholding Combustion Processes
NASA Technical Reports Server (NTRS)
Pellett, G. L.; Bruno, Claudio; Chinitz, W.
2002-01-01
This paper offers a detailed review and analysis of more than 100 papers on the physics and chemistry of scramjet ignition and flameholding combustion processes, and the known effects of air vitiation on these processes. The paper attempts to explain vitiation effects in terms of known chemical kinetics and flame propagation phenomena. Scaling methodology is also examined, and a highly simplified Damkoehler scaling technique based on OH radical production/destruction is developed to extrapolate ground test results, affected by vitiation, to flight testing conditions. The long term goal of this effort is to help provide effective means for extrapolating ground test data to flight, and thus to reduce the time and expense of both ground and flight testing.
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Extrapolation of toxic indices among test objects
Tichý, Miloň; Rucki, Marián; Roth, Zdeněk; Hanzlíková, Iveta; Vlková, Alena; Tumová, Jana; Uzlová, Rút
2010-01-01
Oligochaeta Tubifex tubifex, fish fathead minnow (Pimephales promelas), hepatocytes isolated from rat liver and ciliated protozoan are absolutely different organisms and yet their acute toxicity indices correlate. Correlation equations for special effects were developed for a large heterogeneous series of compounds (QSAR, quantitative structure-activity relationships). Knowing those correlation equations and their statistic evaluation, one can extrapolate the toxic indices. The reason is that a common physicochemical property governs the biological effect, namely the partition coefficient between two unmissible phases, simulated generally by n-octanol and water. This may mean that the transport of chemicals towards a target is responsible for the magnitude of the effect, rather than reactivity, as one would assume suppose. PMID:21331180
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Ecotoxicity of diethylene glycol and risk assessment for marine environment.
Manfra, L; Tornambè, A; Savorelli, F; Rotini, A; Canepa, S; Mannozzi, M; Cicero, A M
2015-03-02
Diethylene glycol (DEG) is a chemical compound used during offshore oil activities to prevent hydrate formation, and it may be released into the sea. A full ecotoxicological characterization is required according to European and Italian regulations for chemical substances. We have evaluated long-term toxic effects of DEG on indicator species of the marine environment as algae (Phaeodactylum tricornutum), crustaceans (Artemia franciscana), molluscs (Tapes philippinarum) and fish (Dicentrarchus labrax). A range of no observed effect concentrations (365-25,000 mg/L) has been identified. Based on the toxicity results and the ratio between predicted environmental concentration and predicted no-effect concentration, we have estimated the maximum allowable value of DEG in the marine environment. Copyright © 2014 Elsevier B.V. All rights reserved.
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Nguyen, Nhung H A; Von Moos, Nadia R; Slaveykova, Vera I; Mackenzie, Katrin; Meckenstock, Rainer U; Thűmmler, Silke; Bosch, Julian; Ševců, Alena
2018-06-15
As nanoremediation strategies for in-situ groundwater treatment extend beyond nanoiron-based applications to adsorption and oxidation, ecotoxicological evaluations of newly developed materials are required. The biological effects of four new materials with different iron (Fe) speciations ([i] FerMEG12 - pristine flake-like milled Fe(0) nanoparticles (nZVI), [ii] Carbo-Iron ® - Fe(0)-nanoclusters containing activated carbon (AC) composite, [iii] Trap-Ox® Fe-BEA35 (Fe-zeolite) - Fe-doped zeolite, and [iv] Nano-Goethite - 'pure' FeOOH) were studied using the unicellular green alga Chlamydomonas sp. as a model test system. Algal growth rate, chlorophyll fluorescence, efficiency of photosystem II, membrane integrity and reactive oxygen species (ROS) generation were assessed following exposure to 10, 50 and 500 mg L -1 of the particles for 2 h and 24 h. The particles had a concentration-, material- and time-dependent effect on Chlamydomonas sp., with increased algal growth rate after 24 h. Conversely, significant intracellular ROS levels were detected after 2 h, with much lower levels after 24 h. All Fe-nanomaterials displayed similar Z-average sizes and zeta-potentials at 2 h and 24 h. Effects on Chlamydomonas sp. decreased in the order FerMEG12 > Carbo-Iron® > Fe-zeolite > Nano-Goethite. Ecotoxicological studies were challenged due to some particle properties, i.e. dark colour, effect of constituents and a tendency to agglomerate, especially at high concentrations. All particles exhibited potential to induce significant toxicity at high concentrations (500 mg L -1 ), though such concentrations would rapidly decrease to mg or µg L -1 in aquatic environments, levels harmless to Chlamydomonas sp. The presented findings contribute to the practical usage of particle-based nanoremediation in environmental restoration. Copyright © 2018. Published by Elsevier Inc.
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Uncertainty factors in screening ecological risk assessments
DOE Office of Scientific and Technical Information (OSTI.GOV)
Duke, L.D.; Taggart, M.
2000-06-01
The hazard quotient (HQ) method is commonly used in screening ecological risk assessments (ERAs) to estimate risk to wildlife at contaminated sites. Many ERAs use uncertainty factors (UFs) in the HQ calculation to incorporate uncertainty associated with predicting wildlife responses to contaminant exposure using laboratory toxicity data. The overall objective was to evaluate the current UF methodology as applied to screening ERAs in California, USA. Specific objectives included characterizing current UF methodology, evaluating the degree of conservatism in UFs as applied, and identifying limitations to the current approach. Twenty-four of 29 evaluated ERAs used the HQ approach: 23 of thesemore » used UFs in the HQ calculation. All 24 made interspecies extrapolations, and 21 compensated for its uncertainty, most using allometric adjustments and some using RFs. Most also incorporated uncertainty for same-species extrapolations. Twenty-one ERAs used UFs extrapolating from lowest observed adverse effect level (LOAEL) to no observed adverse effect level (NOAEL), and 18 used UFs extrapolating from subchronic to chronic exposure. Values and application of all UF types were inconsistent. Maximum cumulative UFs ranged from 10 to 3,000. Results suggest UF methodology is widely used but inconsistently applied and is not uniformly conservative relative to UFs recommended in regulatory guidelines and academic literature. The method is limited by lack of consensus among scientists, regulators, and practitioners about magnitudes, types, and conceptual underpinnings of the UF methodology.« less
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ECOTOX knowledgebase: New tools for data visualization and database interoperability
The ECOTOXicology knowledgebase (ECOTOX) is a comprehensive, curated database that summarizes toxicology data fromsingle chemical exposure studies to terrestrial and aquatic organisms. The ECOTOX Knowledgebase provides risk assessors and researchers consistent information on toxi...
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ECOTOX database; new additions and future direction
The ECOTOXicology database (ECOTOX) is a comprehensive, publicly available knowledgebase developed and maintained by ORD/NHEERL. It is used for environmental toxicity data on aquatic life, terrestrial plants and wildlife. Publications are identified for potential applicability af...
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Predictive Ecotoxicology in the 21st Century
Ecological risk assessments have long relied on apical data on survival, growth/development, and reproduction, generated in animal toxicity tests and the application of uncertainty factors and conservative (typically) assumptions as a basis for decision-making. However, advances ...
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APPROACHES IN PROTEOMICS AND GENOMICS FOR ECO-TOXICOLOGY
A new area of scientific investigation, coined toxicogenomics, enables researchers to understand and study the interaction between the environment and inherited genetic characteristics. This understanding will be critical to fully appreciate the response of organisms to environm...
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Kloos, Karin; Schloter, Michael; Meyer, Ortwin
2006-11-01
Acid resins are residues produced in a recycling process for used oils that was in use in the forties and fifties of the last century. The resin-like material is highly contaminated with mineral oil hydrocarbons, extremely acidic and co-contaminated with substituted and aromatic hydrocarbons, and heavy metals. To determine the potential for microbial biodegradation the acid resin deposit and its surroundings were screened for microbial activity by soil respiration measurements. No microbial activity was found in the core deposit. However, biodegradation of hydrocarbons was possible in zones with a lower degree of contamination surrounding the deposit. An extreme acidophilic microbial community was detected close to the core deposit. With a simple ecotoxicological approach it could be shown that the pure acid resin that formed the major part of the core deposit, was toxic to the indigenous microflora due to its extremely low pH of 0-1.
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Korshun, M; Dema, O; Kucherenko, O; Ruda, T; Korshun, O; Gorbachevskyi, R; Pelio, I; Antonenko, A
2016-07-01
Application of pesticides in modern agriculture is a powerful permanent risk factor for public health and the natural environment. The aim of the study was a comparative hygienic assessment of soil pollution hazards by the most widely used herbicides of different chemical classes (sulfonylureas, imidazolinones, pyrimidinyl (thio) benzoates, semicarbazones). Hygienic field experiment for studying of the dynamics of residual amounts of the test substances in the soil under different climatic zones of Ukraine was conducted. Half life periods (DT50) or herbicides in soil were calculated using the method of mathematical modeling. Ecotoxicological risk of herbicides on ecosystems and ecological communities was determined. It was established that bispyribac-sodium (pyrimidinyl (thio) benzoates) and imidazolinones are persist the longest time in soil and most rapidly degradable is diflufenzopyr (semicarbazone); ecotoxicological risk of the studied herbicides for terrestrial biocenoses of Ukraine by 4-6 orders of magnitude lower than dihlordifeniltrihlormetilmetan (DDT).
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Angerville, Ruth; Perrodin, Yves; Bazin, Christine; Emmanuel, Evens
2013-01-01
Discharges of Combined Sewer Overflows (CSOs) into periurban rivers present risks for the concerned aquatic ecosystems. In this work, a specific ecotoxicological risk assessment methodology has been developed as management tool to municipalities equipped with CSOs. This methodology comprises a detailed description of the spatio-temporal system involved, the choice of ecological targets to be preserved, and carrying out bioassays adapted to each compartment of the river receiving CSOs. Once formulated, this methodology was applied to a river flowing through the outskirts of the city of Lyon in France. The results obtained for the scenario studied showed a moderate risk for organisms of the water column and a major risk for organisms of the benthic and hyporheic zones of the river. The methodology enabled identifying the critical points of the spatio-temporal systems studied, and then making proposals for improving the management of CSOs. PMID:23812025
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Arsenic rich iron plaque on macrophyte roots--an ecotoxicological risk?
Taggart, M A; Mateo, R; Charnock, J M; Bahrami, F; Green, A J; Meharg, A A
2009-03-01
Arsenic is known to accumulate with iron plaque on macrophyte roots. Three to four years after the Aznalcóllar mine spill (Spain), residual arsenic contamination left in seasonal wetland habitats has been identified in this form by scanning electron microscopy. Total digestion has determined arsenic concentrations in thoroughly washed 'root+plaque' material in excess of 1000 mg kg(-1), and further analysis using X-ray absorption spectroscopy suggests arsenic exists as both arsenate and arsenite. Certain herbivorous species feed on rhizomes and bulbs of macrophytes in a wide range of global environments, and the ecotoxicological impact of consuming arsenic rich iron plaque associated with such food items remains to be quantified. Here, greylag geese which feed on Scirpus maritimus rhizome and bulb material in areas affected by the Aznalcóllar spill are shown to have elevated levels of arsenic in their feces, which may originate from arsenic rich iron plaque.
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Vink, J P M; Meeussen, J C L
2007-08-01
The chemical speciation model BIOCHEM was extended with ecotoxicological transfer functions for uptake of metals (As, Cd, Cu, Ni, Pb, and Zn) by plants and soil invertebrates. It was coupled to the object-oriented framework ORCHESTRA to achieve a flexible and dynamic decision support system (DSS) to analyse natural or anthropogenic changes that occur in river systems. The DSS uses the chemical characteristics of soils and sediments as input, and calculates speciation and subsequent uptake by biota at various scenarios. Biotic transfer functions were field-validated, and actual hydrological conditions were derived from long-term monitoring data. The DSS was tested for several scenarios that occur in the Meuse catchment areas, such as flooding and sedimentation of riverine sediments on flood plains. Risks are expressed in terms of changes in chemical mobility, and uptake by flood plain key species (flora and fauna).
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Vemer, Pepijn; Rutten-van Mölken, Maureen P M H; Kaper, Janneke; Hoogenveen, Rudolf T; van Schayck, C P; Feenstra, Talitha L
2010-06-01
Smoking cessation can be encouraged by reimbursing the costs of smoking cessation support (SCS). The short-term efficiency of reimbursement has been evaluated previously. However, a thorough estimate of the long-term cost-utility is lacking. To evaluate long-term effects of reimbursement of SCS. Results from a randomized controlled trial were extrapolated to long-term outcomes in terms of health care costs and (quality adjusted) life years (QALY) gained, using the Chronic Disease Model. Our first scenario was no reimbursement. In a second scenario, the short-term cessation rates from the trial were extrapolated directly. Sensitivity analyses were based on the trial's confidence intervals. In the third scenario the additional use of SCS as found in the trial was combined with cessation rates from international meta-analyses. Intervention costs per QALY gained compared to the reference scenario were approximately euro1200 extrapolating the trial effects directly, and euro4200 when combining the trial's use of SCS with the cessation rates from the literature. Taking all health care effects into account, even costs in life years gained, resulted in an estimated incremental cost-utility of euro4500 and euro7400, respectively. In both scenarios costs per QALY remained below euro16 000 in sensitivity analyses using a life-time horizon. Extrapolating the higher use of SCS due to reimbursement led to more successful quitters and a gain in life years and QALYs. Accounting for overheads, administration costs and the costs of SCS, these health gains could be obtained at relatively low cost, even when including costs in life years gained. Hence, reimbursement of SCS seems to be cost-effective from a health care perspective.
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Reproductive Effects of Two Polybrominated Diphenyl Ethers on the Rotifer Brachionus plicatilis.
Zhang, Jing; Wang, You; Zhou, Bin; Sun, Kai-Ming; Tang, Xuexi
2016-08-01
The effects of two polybrominated diphenyl ethers (PBDEs) on the reproduction of the rotifer Brachionus plicatilis were investigated. Results showed that sexual maturation was promoted by tetra-brominated diphenyl ether-47 (BDE-47) and deca-brominated diphenyl ether-209 (BDE-209), whereas fecundity was inhibited by BDE-47, but promoted by BDE-209. Additionally, both PBDEs affected the expression of two genes, vasa and nanos mRNA, related to rotifer reproduction. This suggests a possible regulatory molecular mechanism at the transcriptional level. Our research extends the current knowledge of the ecotoxicological mechanism induced by PBDEs and provides further essential information for assessing the risks of PBDE contamination in marine ecosystems.
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The forecast for RAC extrapolation: mostly cloudy.
Goldman, Elizabeth; Jacobs, Robert; Scott, Ellen; Scott, Bonnie
2011-09-01
The current statutory and regulatory guidance for recovery audit contractor (RAC) extrapolation leaves providers with minimal protection against the process and a limited ability to challenge overpayment demands. Providers not only should understand the statutory and regulatory basis for extrapolation forecast, but also should be able to assess their extrapolation risk and their recourse through regulatory safeguards against contractor error. Providers also should aggressively appeal all incorrect RAC denials to minimize the potential impact of extrapolation.
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Surface dose measurements with commonly used detectors: a consistent thickness correction method
Higgins, Patrick
2015-01-01
The purpose of this study was to review application of a consistent correction method for the solid state detectors, such as thermoluminescent dosimeters (chips (cTLD) and powder (pTLD)), optically stimulated detectors (both closed (OSL) and open (eOSL)), and radiochromic (EBT2) and radiographic (EDR2) films. In addition, to compare measured surface dose using an extrapolation ionization chamber (PTW 30‐360) with other parallel plate chambers RMI‐449 (Attix), Capintec PS‐033, PTW 30‐329 (Markus) and Memorial. Measurements of surface dose for 6 MV photons with parallel plate chambers were used to establish a baseline. cTLD, OSLs, EDR2, and EBT2 measurements were corrected using a method which involved irradiation of three dosimeter stacks, followed by linear extrapolation of individual dosimeter measurements to zero thickness. We determined the magnitude of correction for each detector and compared our results against an alternative correction method based on effective thickness. All uncorrected surface dose measurements exhibited overresponse, compared with the extrapolation chamber data, except for the Attix chamber. The closest match was obtained with the Attix chamber (−0.1%), followed by pTLD (0.5%), Capintec (4.5%), Memorial (7.3%), Markus (10%), cTLD (11.8%), eOSL (12.8%), EBT2 (14%), EDR2 (14.8%), and OSL (26%). Application of published ionization chamber corrections brought all the parallel plate results to within 1% of the extrapolation chamber. The extrapolation method corrected all solid‐state detector results to within 2% of baseline, except the OSLs. Extrapolation of dose using a simple three‐detector stack has been demonstrated to provide thickness corrections for cTLD, eOSLs, EBT2, and EDR2 which can then be used for surface dose measurements. Standard OSLs are not recommended for surface dose measurement. The effective thickness method suffers from the subjectivity inherent in the inclusion of measured percentage depth‐dose curves and is not recommended for these types of measurements. PACS number: 87.56.‐v PMID:26699319
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Palma, Patrícia; Alvarenga, Paula; Palma, Vera; Matos, Cláudia; Fernandes, Rosa Maria; Soares, Amadeu; Barbosa, Isabel Rita
2010-03-01
Freshwater reservoirs can be impacted by several hazardous substances through inputs from agricultural activity, sewage discharges, and groundwater leaching and runoff. The water quality assessment is very important for implementation of the monitoring and remediation programs to minimize the risk promoted by hazardous substances in aquatic ecosystems. Evaluation of the degree of contamination of aquatic environments must not take in account only its chemical characterization but it must be complemented with biological assays, which determine potential toxic effects and allows an integrated evaluation of its effects in populations and aquatic ecosystem communities. The application of this type of strategy has clear advantages allowing a general evaluation of the effects from all the water components, including those due to unknown substances and synergic, antagonistic, or additive effects. There are only a few studies that reported ecotoxicological acute end points, for the assessment of surface water quality, and the relationship among toxicity results and the anthropogenic pollution sources and the seasonal period. The aim of this study was to assess the ecotoxicological characterization of the surface water from Alqueva reservoir (South of Portugal) and to evaluate the influence of anthropogenic sources of pollution and their seasonal variation in its toxicity. The construction of Alqueva reservoir was recently finished (2002) and, to our knowledge, an ecotoxicological assessment of its surface water has not been performed. Because of that, no information is available on the possible impact of pollutants on the biota. The surface water toxicity was assessed using acute and chronic bioassays. The results are to be used for developing a monitoring program, including biological methods. Water samples were collected during 2006-2007, at each of the nine sampling sites selected in Alqueva reservoir. These sampling points allow an assessment at the upstream (Sra. Ajuda, Alcarrache, Alamos-Captação), at the middle (Alqueva-Montante, Alqueva-Mourão, Lucefecit), and at the downstream of the water line (Alqueva-Jusante; Ardila-confluência; Moinho das Barcas). The campaigns occurred in February, March, May, July, September, and November of 2006 and February, March, and May of 2007. The rainy season comprised November, February, and March, and the dry season included May, July, and September. A total of 81 samples were collected during the study period. The physical-chemical parameters were analyzed following standard and recommended methods of analysis (APHA et al. 1998). The pesticide analyses were performed using gas chromatography according to DIN EN ISO 6468 (1996). Surface water ecotoxicity was evaluated using the following bioassays: Vibrio fischeri luminescence inhibition, Thamnocephalus platyurus mortality, and Daphnia magna immobilization and reproduction assay. The Spearman rank correlation coefficients were used to evaluate the associations between the water sample physicochemical properties (from each sampling station in each season) and the acute and chronic toxicological effects, with a level of significance p < 0.05. In the acute toxicity study, the species that was found to be the most sensitive was T. platyurus. T. platyurus detected a higher number of toxic water samples during the dry season. Concerning the luminescent inhibition of V. fischeri, the results showed that this organism detected a great number of toxic water samples in rainy seasons. The water samples, which promoted higher toxic effects towards this species, were from the north and from the middle of the reservoir. The correlation analysis showed that V. fischeri luminescent inhibition (%) was positively correlated with total phosphorus, chlorpyrifos, iron, and arsenic. T. platyurus mortality (%) was positively correlated with the water pH, 5-day biochemical oxygen demand (BOD(5)), chlorides, atrazine, simazine, terbuthylazine, and endosulfan sulfate contents. Although the surface waters did not promote acute toxicity to the crustacean D. magna, in the chronic exposure, a significant decrease in the number of juveniles per female was observed, mainly at the dry period. The number of juveniles per female, in the reproduction test of D. magna, was negatively correlated with pH, temperature, BOD(5), chloride, atrazine, simazine, terbuthylazine, and endosulfan sulfate. The water toxicity of the Alqueva water might be due principally to the intensive agriculture activities surrounding the reservoir and to the municipal wastewater discharges. The physicochemical parameters and the pesticide concentrations indicated that the water quality was worse in the north part of the reservoir system. These results are characteristic of the majority of reservoirs, once the construction of the dam promoted, by itself, the impounding of water flow and the increase of compound residence time. The toxicity tests corroborate with the chemical characterization. Acute toxicity of Alqueva water may be a result of the effect promoted by chlorpyrifos, endosulfan sulfate, phosphorus, and iron. Chronic toxicity may be a result of the effect of herbicides, arsenic, organic matter, endosulfan sulfate in mixture. Hence, the water toxicity of the Alqueva might be due principally to the intensive agriculture activities surrounding the reservoir and to the municipal wastewater discharges. This study has shown that a large number of samples from different sites of the Alqueva reservoir contained potentially toxic contaminants. The sites with impaired water quality were those located at the north of the reservoir and in the surrounding areas of intensive agricultural activity. The results demonstrated that the use of a screening of acute and chronic toxicity tests with organisms from different trophic levels and with distinct sensibilities allowed the detections of several patterns of toxicity from spatial and temporal variability promoted by natural or anthropogenic sources. The chronic responses showed, especially in the dry season, that some of the species belonging to this aquatic ecosystem might be at risk. The V. fischeri and T. platyurus are two species that should be used in the acute bioassays for the ecotoxicological monitoring programs of this reservoir. It is recommended that other species, such as a productive organism (algae), be included in the next study, once the water reservoir had high levels of herbicides. Ecotoxicological assessment of surface water must integrate initial screening based on acute tests followed always by chronic bioassays. The results implicitly suggest that the implementation of processes of remediation by reducing pollutant input into the reservoir and by the implementation of water treatment processes is important and necessary.
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Brennan, Scott F; Cresswell, Andrew G; Farris, Dominic J; Lichtwark, Glen A
2017-11-07
Ultrasonography is a useful technique to study muscle contractions in vivo, however larger muscles like vastus lateralis may be difficult to visualise with smaller, commonly used transducers. Fascicle length is often estimated using linear trigonometry to extrapolate fascicle length to regions where the fascicle is not visible. However, this approach has not been compared to measurements made with a larger field of view for dynamic muscle contractions. Here we compared two different single-transducer extrapolation methods to measure VL muscle fascicle length to a direct measurement made using two synchronised, in-series transducers. The first method used pennation angle and muscle thickness to extrapolate fascicle length outside the image (extrapolate method). The second method determined fascicle length based on the extrapolated intercept between a fascicle and the aponeurosis (intercept method). Nine participants performed maximal effort, isometric, knee extension contractions on a dynamometer at 10° increments from 50 to 100° of knee flexion. Fascicle length and torque were simultaneously recorded for offline analysis. The dual transducer method showed similar patterns of fascicle length change (overall mean coefficient of multiple correlation was 0.76 and 0.71 compared to extrapolate and intercept methods respectively), but reached different absolute lengths during the contractions. This had the effect of producing force-length curves of the same shape, but each curve was shifted in terms of absolute length. We concluded that dual transducers are beneficial for studies that examine absolute fascicle lengths, whereas either of the single transducer methods may produce similar results for normalised length changes, and repeated measures experimental designs. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Alonso, Álvaro; Figueroa, Ricardo; Castro-Díez, Pilar
2017-05-01
The water demand for human activities is rapidly increasing in developing countries. Under these circumstances, preserving aquatic ecosystems should be a priority which requires the development of quality criteria. In this study we perform a preliminary prioritization of the risky substances based on reported ecotoxicological studies and guidelines for the Biobío watershed (Central Chile). Our specific aims are (1) reviewing the scientific information on the aquatic pollution of this watershed, (2) determining the presence and concentration of potential toxic substances in water, sediment and effluents, (3) searching for quality criteria developed by other countries for the selected substances and (4) prioritizing the most risky substances by means of deterministic ecotoxicological risk assessment. We found that paper and mill industries were the main sources of point pollution, while forestry and agriculture were mostly responsible for non-point pollution. The most risky organic substances in the water column were pentachlorophenol and heptachlor, while the most relevant inorganic ones were aluminum, copper, unionized ammonia and mercury. The most risky organic and inorganic substances in the sediment were phenanthrene and mercury, respectively. Our review highlights that an important effort has been done to monitor pollution in the Biobío watershed. However there are emerging pollutants and banned compounds-especially in sediments-that require to be monitored. We suggest that site-specific water quality criteria and sediment quality criteria should be developed for the Biobío watershed, considering the toxicity of mixtures of chemicals to endemic species, and the high natural background level of aluminum in the Biobío.
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Garaventa, Francesca; Gambardella, Chiara; Di Fino, Alessio; Pittore, Massimiliano; Faimali, Marco
2010-03-01
In this study, we investigated the possibility to improve a new behavioural bioassay (Swimming Speed Alteration test-SSA test) using larvae of marine cyst-forming organisms: e.g. the brine shrimp Artemia sp. and the rotifer Brachionus plicatilis. Swimming speed was investigated as a behavioural end-point for application in ecotoxicology studies. A first experiment to analyse the linear swimming speed of the two organisms was performed to verify the applicability of the video-camera tracking system, here referred to as Swimming Behavioural Recorder (SBR). A second experiment was performed, exposing organisms to different toxic compounds (zinc pyrithione, Macrotrol MT-200, and Eserine). Swimming speed alteration was analyzed together with mortality. The results of the first experiment indicate that SBR is a suitable tool to detect linear swimming speed of the two organisms, since the values have been obtained in accordance with other studies using the same organisms (3.05 mm s(-1) for Artemia sp. and 0.62 mm s(-1) for B. plicatilis). Toxicity test results clearly indicate that swimming speed of Artemia sp. and B. plicatilis is a valid behavioural end-point to detect stress at sub-lethal toxic substance concentrations. Indeed, alterations in swimming speed have been detected at toxic compound concentrations as low as less then 0.1-5% of their LC(50) values. In conclusion, the SSA test with B. plicatilis and Artemia sp. can be a good behavioural integrated output for application in marine ecotoxicology and environmental monitoring programs.
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The sperm motility pattern in ecotoxicological tests. The CRYO-Ecotest as a case study.
Fabbrocini, Adele; D'Adamo, Raffaele; Del Prete, Francesco; Maurizio, Daniela; Specchiulli, Antonietta; Oliveira, Luis F J; Silvestri, Fausto; Sansone, Giovanni
2016-01-01
Changes in environmental stressors inevitably lead to an increasing need for innovative and more flexible monitoring tools. The aim of this work has been the characterization of the motility pattern of the cryopreserved sea bream semen after exposure to a dumpsite leachate sample, for the identification of the best representative parameters to be used as endpoints in an ecotoxicological bioassay. Sperm motility has been evaluated either by visual and by computer-assisted analysis; parameters concerning motility on activation and those describing it in the times after activation (duration parameters) have been assessed, discerning them in terms of sensitivity, reliability and methodology of assessment by means of multivariate analyses. The EC50 values of the evaluated endpoints ranged between 2.3 and 4.5ml/L, except for the total motile percentage (aTM, 7.0ml/L), which proved to be the less sensitive among all the tested parameters. According to the multivariate analyses, a difference in sensitivity among "activation" endpoints in respect of "duration" ones can be inferred; on the contrary, endpoints seem to be equally informative either describing total motile sperm or the rapid sub-population, as well as the assessment methodology seems to be not discriminating. In conclusion, the CRYO-Ecotest is a multi-endpoint bioassay that can be considered a promising innovative ecotoxicological tool, characterized by a high plasticity, as its endpoints can be easy tailored each time according to the different needs of the environmental quality assessment programs. Copyright © 2015 Elsevier Inc. All rights reserved.
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NASA Astrophysics Data System (ADS)
Alonso, Álvaro; Figueroa, Ricardo; Castro-Díez, Pilar
2017-05-01
The water demand for human activities is rapidly increasing in developing countries. Under these circumstances, preserving aquatic ecosystems should be a priority which requires the development of quality criteria. In this study we perform a preliminary prioritization of the risky substances based on reported ecotoxicological studies and guidelines for the Biobío watershed (Central Chile). Our specific aims are (1) reviewing the scientific information on the aquatic pollution of this watershed, (2) determining the presence and concentration of potential toxic substances in water, sediment and effluents, (3) searching for quality criteria developed by other countries for the selected substances and (4) prioritizing the most risky substances by means of deterministic ecotoxicological risk assessment. We found that paper and mill industries were the main sources of point pollution, while forestry and agriculture were mostly responsible for non-point pollution. The most risky organic substances in the water column were pentachlorophenol and heptachlor, while the most relevant inorganic ones were aluminum, copper, unionized ammonia and mercury. The most risky organic and inorganic substances in the sediment were phenanthrene and mercury, respectively. Our review highlights that an important effort has been done to monitor pollution in the Biobío watershed. However there are emerging pollutants and banned compounds—especially in sediments—that require to be monitored. We suggest that site-specific water quality criteria and sediment quality criteria should be developed for the Biobío watershed, considering the toxicity of mixtures of chemicals to endemic species, and the high natural background level of aluminum in the Biobío.
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Drzewicz, Przemysław; Drobniewska, Agata; Sikorska, Katarzyna; Nałęcz-Jawecki, Grzegorz
2018-05-14
A large amount of pharmaceuticals are flushed to environment via sewage system. The compounds are persistent in environment and are very difficult to remove in drinking water treatment processes. Degradation of fluoxetine (FLU) and fluvoxamine (FLX) by ferrate(VI) were investigated. For the 10 mg/L of FLU and FLX, 35% and 50% of the compounds were degraded in the presence of 50 mg/L FeO 4 2- within 10 minutes, respectively. After 10 minutes of the reaction, degradation of FLU and FLX is affected by formation of by-products which were likely more reactive with ferrate and competed in the reaction with FeO 4 2- . In the case of FLU, the identified degradation by-products were hydrofluoxetine, N-methyl-3-phenyl-2-propen-1-amine, 4-(trifluoromethyl)phenol and 1-{[(1R,S)-1-Phenyl-2-propen-1-yl]oxy}-4-(trifluoromethyl)benzene. In the case of FLX, the degradation by-products were fluvoxamine acid and 5-methoxy-1-[4-(trifluoromethyl)phenyl]pent-2-en-1-imine. The results of the ecotoxicological study based on protozoa Spirostomum ambiguum have shown that 50 mg/L FeO 4 2- reduced toxicity of 10 mg/L of FLU and FLX by around 50%. However, in the case of FLX, the results of the ecotoxicological study suggested formation of slightly more toxic compound(s) than FLX during reaction with FeO 4 2- . Application of ferrate(VI) is a viable option for drinking water treatment process; however, caution is needed due to formation of by-products with unknown human health risk.
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Technical Manual for MCestimate
The analysis of competing risks has a long history in human health research, but has received limited formal attention in wildlife ecology and ecotoxicology (Heisey and Patterson 2006). Informally, however, the concept of competing risks has arisen many times in these disciplines...
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The analysis of competing risks has a long history in human health research, but has received limited formal attention in wildlife ecology and ecotoxicology (Heisey and Patterson 2006). Informally, however, the concept of competing risks has arisen many times in these disciplines...
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ECOTOX knowledgebase: Search features and customized reports
The ECOTOXicology knowledgebase (ECOTOX) is a comprehensive, publicly available knowledgebase developed and maintained by ORD/NHEERL. It is used for environmental toxicity data on aquatic life, terrestrial plants and wildlife. ECOTOX has the capability to refine and filter search...
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ECOTOX Knowledgebase: New tools for data visualization and database interoperability -Poster
The ECOTOXicology knowledgebase (ECOTOX) is a comprehensive, curated database that summarizes toxicology data from single chemical exposure studies to terrestrial and aquatic organisms. The ECOTOX Knowledgebase provides risk assessors and researchers consistent information on tox...
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ECOTOX Knowledgebase: New tools for data visualization and database interoperability (poster)
The ECOTOXicology knowledgebase (ECOTOX) is a comprehensive, curated database that summarizes toxicology data from single chemical exposure studies to terrestrial and aquatic organisms. The ECOTOX Knowledgebase provides risk assessors and researchers consistent information on tox...
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Herbicide drift affects plant and arthropod communities
USDA-ARS?s Scientific Manuscript database
Field edges, old fields, and other semi-natural habitats in agricultural landscapes support diverse plant communities that help sustain pollinators, predators, and other beneficial arthropods. These plant and arthropod communities may be at persistent ecotoxicological risk from herbicides applied to...
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DNA Microarray-based Ecotoxicological Biomarker Discovery in a Small Fish Model Species
This paper addresses several issues critical to use of zebrafish oligonucleotide microarrays for computational toxicology research on endocrine disrupting chemicals using small fish models, and more generally, the use of microarrays in aquatic toxicology.
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ECOTOXICOLOGY OF TROPICAL MARINE ECOSYSTEMS. (R825158)
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
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Behavorial assessments of larval zebrafish neurotoxicology
Fishes have long been a popular organism in ecotoxicology research, and are increasingly used in human health research as an alternative animal model for chemical screening. Our laboratory incorporates a zebrafish (Danio rerio) embryo/larval assay to screen chemicals for developm...
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Toxicogenomics Applied to Ecotoxicology
This chapter focuses on evaluation of the current practice of ecotoxicogenomics, less than a decade after the term was coined, as the field continues to evolve. We describe major applications of genomic approaches to define modes/mechanisms of action and derive biologically-base...
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Measurements of the Absorption by Auditorium SEATING—A Model Study
NASA Astrophysics Data System (ADS)
BARRON, M.; COLEMAN, S.
2001-01-01
One of several problems with seat absorption is that only small numbers of seats can be tested in standard reverberation chambers. One method proposed for reverberation chamber measurements involves extrapolation when the absorption coefficient results are applied to actual auditoria. Model seat measurements in an effectively large model reverberation chamber have allowed the validity of this extrapolation to be checked. The alternative barrier method for reverberation chamber measurements was also tested and the two methods were compared. The effect on the absorption of row-row spacing as well as absorption by small numbers of seating rows was also investigated with model seats.
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López-Mondéjar, Rubén; Antón, Anabel; Raidl, Stefan; Ros, Margarita; Pascual, José Antonio
2010-04-01
The species of the genus Trichoderma are used successfully as biocontrol agents against a wide range of phytopathogenic fungi. Among them, Trichoderma harzianum is especially effective. However, to develop more effective fungal biocontrol strategies in organic substrates and soil, tools for monitoring the control agents are required. Real-time PCR is potentially an effective tool for the quantification of fungi in environmental samples. The aim of this study consisted of the development and application of a real-time PCR-based method to the quantification of T. harzianum, and the extrapolation of these data to fungal biomass values. A set of primers and a TaqMan probe for the ITS region of the fungal genome were designed and tested, and amplification was correlated to biomass measurements obtained with optical microscopy and image analysis, of the hyphal length of the mycelium of the colony. A correlation of 0.76 between ITS copies and biomass was obtained. The extrapolation of the quantity of ITS copies, calculated based on real-time PCR data, into quantities of fungal biomass provides potentially a more accurate value of the quantity of soil fungi. Copyright 2009 Elsevier Ltd. All rights reserved.
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Kohlschmid, E; Ruf, D
2016-12-01
Testing of effects on earthworms and non-target foliar arthropods is an integral part of the ecotoxicological risk assessment for the authorization of plant protection products. According to the new data requirements, which came into force in 2014 for active substances and in 2016 for plant protection products, the chronic earthworm toxicity test with Eisenia fetida based on reproductive, growth, and behavioral effects instead of the acute earthworm toxicity test based on mortality, has to be conducted routinely. Additional testing of effects on soil arthropods (Folsomia candida, Hyposaspis aculeifer) is required if the risk assessment of foliar applications raises concerns regarding non-target foliar arthropods (Aphidius rhopalosiphi, Typhlodromus pyri) or if the product is applied directly on or into the soil. Thus, it was investigated whether the sublethal earthworm endpoint is more sensitive than the sublethal soil arthropod endpoint for different types of pesticides and whether the risk assessment for non-target arthropods would trigger the testing of effects on soil arthropods in the cases where soil arthropods are more sensitive than earthworms. Toxicity data were obtained from Swiss ecotoxicological database, EFSA Conclusions and scientific literature. For insecticides and herbicides, no general conclusion regarding differences in sensitivity of either earthworms or soil arthropods based on sublethal endpoints were possible. For fungicides, the data indicated that in general, earthworms seemed to be more sensitive than soil arthropods. In total, the sublethal F. candida or H. aculeifer endpoint was lower than the sublethal E. fetida endpoint for 23 (34 %) out of 68 active substances. For 26 % of these 23 active substances, testing of soil arthropods would not have been triggered due to the new data requirement. These results based on sublethal endpoints show that earthworms and soil arthropods differ in sensitivity toward certain active substances and that the risk assessment for non-target foliar arthropods did not always trigger soil arthropod testing in the cases where soil arthropods were more sensitive than earthworms.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Lajmanovich, Rafael C., E-mail: lajmanovich@hotmail.com; Faculty of Biochemistry and Biological Sciences; Junges, Celina M.
The effects of commercial formulations of Bacillus thuringiensisvar.israelensis (Bti) on non-target organisms are still a matter of debate; in amphibians, the risks of Bti are little known. To evaluate the toxicity of a commercial liquid (aqueous suspension, AS) formulation of Bti (Introban{sup ®}) on Leptodactylus latrans tadpoles, including median lethal concentration (LC{sub 50}) and no-and lowest–observed-effect concentrations (NOEC and LOEC, respectively), as well as the possible effects of Bti on oxidative responses, erythrocytes genotoxicity, and histology of the intestines. In the laboratory, tadpoles were exposed to nominal concentrations of 0 (control), 2.5, 5, 10, 20 and 40 mg/L of formulatedmore » Bti-AS. Glutathione S-transferase (GST) and catalase (CAT) activities, as well as formation of erythrocyte nuclear abnormalities (ENAs), and histological effect were measured in tadpoles displaying survival rates >85%. L. latrans tadpoles were sensitive to exposure to Bti-AS, reaching 100% mortality after 48 h of exposure at the highest concentration. Bti-AS induced GST and CAT enzymes and genotoxicity (erythrocyte's nuclear abnormalities), and caused intestine's histopathology. Our results demonstrate that toxicity of Bti-AS is dose-dependent for L. latrans tadpoles and that sublethal exposure alters enzymes of oxidative stress, induces genotoxicity, and causes intestine damage. Further research is needed to evaluate the ecotoxicological risk of the massive use of Bti formulations on amphibian populations that commonly used suburban wastewater or urban waterbodies to reproduce and where this biopesticide is frequently applied. - Highlights: • An ecotoxicological evaluation of a Bti formulation on amphibian was conducted. • Toxicity of Bti-AS was dose-dependent for Leptodactylus latrans tadpoles. • Sublethal exposure altered the enzymes of oxidative stress (GST and CAT). • Bti-AS was genotoxic because increased MN frequencies (CO: 0.82–2.74‰). • Bti-AS caused the inflammatory infiltration in the lamina propria of intestine.« less
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Organism and population-level ecological models for chemical risk assessment
Ecological risk assessment typically focuses on animal populations as endpoints for regulatory ecotoxicology. Scientists at USEPA are developing models for animal populations exposed to a wide range of chemicals from pesticides to emerging contaminants. Modeled taxa include aquat...
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Zhong, Sheng-hua; Ma, Zheng; Wilson, Colin; Liu, Yan; Flombaum, Jonathan I
2014-01-01
Intuitively, extrapolating object trajectories should make visual tracking more accurate. This has proven to be true in many contexts that involve tracking a single item. But surprisingly, when tracking multiple identical items in what is known as “multiple object tracking,” observers often appear to ignore direction of motion, relying instead on basic spatial memory. We investigated potential reasons for this behavior through probabilistic models that were endowed with perceptual limitations in the range of typical human observers, including noisy spatial perception. When we compared a model that weights its extrapolations relative to other sources of information about object position, and one that does not extrapolate at all, we found no reliable difference in performance, belying the intuition that extrapolation always benefits tracking. In follow-up experiments we found this to be true for a variety of models that weight observations and predictions in different ways; in some cases we even observed worse performance for models that use extrapolations compared to a model that does not at all. Ultimately, the best performing models either did not extrapolate, or extrapolated very conservatively, relying heavily on observations. These results illustrate the difficulty and attendant hazards of using noisy inputs to extrapolate the trajectories of multiple objects simultaneously in situations with targets and featurally confusable nontargets. PMID:25311300
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Spackman, Peter R.; Karton, Amir, E-mail: amir.karton@uwa.edu.au
Coupled cluster calculations with all single and double excitations (CCSD) converge exceedingly slowly with the size of the one-particle basis set. We assess the performance of a number of approaches for obtaining CCSD correlation energies close to the complete basis-set limit in conjunction with relatively small DZ and TZ basis sets. These include global and system-dependent extrapolations based on the A + B/L{sup α} two-point extrapolation formula, and the well-known additivity approach that uses an MP2-based basis-set-correction term. We show that the basis set convergence rate can change dramatically between different systems(e.g.it is slower for molecules with polar bonds and/ormore » second-row elements). The system-dependent basis-set extrapolation scheme, in which unique basis-set extrapolation exponents for each system are obtained from lower-cost MP2 calculations, significantly accelerates the basis-set convergence relative to the global extrapolations. Nevertheless, we find that the simple MP2-based basis-set additivity scheme outperforms the extrapolation approaches. For example, the following root-mean-squared deviations are obtained for the 140 basis-set limit CCSD atomization energies in the W4-11 database: 9.1 (global extrapolation), 3.7 (system-dependent extrapolation), and 2.4 (additivity scheme) kJ mol{sup –1}. The CCSD energy in these approximations is obtained from basis sets of up to TZ quality and the latter two approaches require additional MP2 calculations with basis sets of up to QZ quality. We also assess the performance of the basis-set extrapolations and additivity schemes for a set of 20 basis-set limit CCSD atomization energies of larger molecules including amino acids, DNA/RNA bases, aromatic compounds, and platonic hydrocarbon cages. We obtain the following RMSDs for the above methods: 10.2 (global extrapolation), 5.7 (system-dependent extrapolation), and 2.9 (additivity scheme) kJ mol{sup –1}.« less
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NASA Astrophysics Data System (ADS)
Spackman, Peter R.; Karton, Amir
2015-05-01
Coupled cluster calculations with all single and double excitations (CCSD) converge exceedingly slowly with the size of the one-particle basis set. We assess the performance of a number of approaches for obtaining CCSD correlation energies close to the complete basis-set limit in conjunction with relatively small DZ and TZ basis sets. These include global and system-dependent extrapolations based on the A + B/Lα two-point extrapolation formula, and the well-known additivity approach that uses an MP2-based basis-set-correction term. We show that the basis set convergence rate can change dramatically between different systems(e.g.it is slower for molecules with polar bonds and/or second-row elements). The system-dependent basis-set extrapolation scheme, in which unique basis-set extrapolation exponents for each system are obtained from lower-cost MP2 calculations, significantly accelerates the basis-set convergence relative to the global extrapolations. Nevertheless, we find that the simple MP2-based basis-set additivity scheme outperforms the extrapolation approaches. For example, the following root-mean-squared deviations are obtained for the 140 basis-set limit CCSD atomization energies in the W4-11 database: 9.1 (global extrapolation), 3.7 (system-dependent extrapolation), and 2.4 (additivity scheme) kJ mol-1. The CCSD energy in these approximations is obtained from basis sets of up to TZ quality and the latter two approaches require additional MP2 calculations with basis sets of up to QZ quality. We also assess the performance of the basis-set extrapolations and additivity schemes for a set of 20 basis-set limit CCSD atomization energies of larger molecules including amino acids, DNA/RNA bases, aromatic compounds, and platonic hydrocarbon cages. We obtain the following RMSDs for the above methods: 10.2 (global extrapolation), 5.7 (system-dependent extrapolation), and 2.9 (additivity scheme) kJ mol-1.
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Effects of sport expertise on representational momentum during timing control.
Nakamoto, Hiroki; Mori, Shiro; Ikudome, Sachi; Unenaka, Satoshi; Imanaka, Kuniyasu
2015-04-01
Sports involving fast visual perception require players to compensate for delays in neural processing of visual information. Memory for the final position of a moving object is distorted forward along its path of motion (i.e., "representational momentum," RM). This cognitive extrapolation of visual perception might compensate for the neural delay in interacting appropriately with a moving object. The present study examined whether experienced batters cognitively extrapolate the location of a fast-moving object and whether this extrapolation is associated with coincident timing control. Nine expert and nine novice baseball players performed a prediction motion task in which a target moved from one end of a straight 400-cm track at a constant velocity. In half of the trials, vision was suddenly occluded when the target reached the 200-cm point (occlusion condition). Participants had to press a button concurrently with the target arrival at the end of the track and verbally report their subjective assessment of the first target-occluded position. Experts showed larger RM magnitude (cognitive extrapolation) than did novices in the occlusion condition. RM magnitude and timing errors were strongly correlated in the fast velocity condition in both experts and novices, whereas in the slow velocity condition, a significant correlation appeared only in experts. This suggests that experts can cognitively extrapolate the location of a moving object according to their anticipation and, as a result, potentially circumvent neural processing delays. This process might be used to control response timing when interacting with moving objects.
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Kechagia, Irene-Ariadne; Kalantzi, Lida; Dokoumetzidis, Aristides
2015-11-01
To extrapolate enalapril efficacy to children 0-6 years old, a pharmacokinetic/pharmacodynamic (PKPD) model was built using literature data, with blood pressure as the PD endpoint. A PK model of enalapril was developed from literature paediatric data up to 16 years old. A PD model of enalapril was fitted to adult literature response vs time data with various doses. The final PKPD model was validated with literature paediatric efficacy observations (diastolic blood pressure (DBP) drop after 2 weeks of treatment) in children of age 6 years and higher. The model was used to predict enalapril efficacy for ages 0-6 years. A two-compartment PK model was chosen with weight, reflecting indirectly age as a covariate on clearance and central volume. An indirect link PD model was chosen to describe drug effect. External validation of the model's capability to predict efficacy in children was successful. Enalapril efficacy was extrapolated to ages 1-11 months and 1-6 years finding the mean DBP drop 11.2 and 11.79 mmHg, respectively. Mathematical modelling was used to extrapolate enalapril efficacy to young children to support a paediatric investigation plan targeting a paediatric-use marketing authorization application. © 2015 Royal Pharmaceutical Society.
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Joint toxicity of methamidophos and cadmium acting on Abelmoschus manihot.
Wang, Xiao-Fei; Zhou, Qi-Xing
2005-01-01
Joint toxicity of methamidophos and cadmium (Cd) on the ornamental Abelmoschus manihot was firstly examined and compared with single-factor effects of the two pollutants using ecotoxicological indexes including the inhibitory rate of seed germination, root elongation and inhibitory concentration 50% (IC50). The results indicated that methamidophos and Cd had unobvious( p > 0.05) effects on seed germination of the ornamental. There were significant( p < 0.05) inhibitory effects of Cd on root elongation of the tested plant. When the concentration of added Cd was low( < 20 mg/L), significant antagonistic effects on root elongation were observed. And synergic effects were observed when Cd was added in high dose( > 20 mg/L). However, the analysis of joint effects indicated that there were antagonistic effects between Cd and methamidophos under all the treatments. At the high concentration of Cd, joint toxicity of methamidophos and Cd was more dependent on concentration of Cd.
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Use of sediment quality guidelines
Wenning, R. J.; Batley, G. E.; Ingersoll, Christopher G.; Moore, David W.
2005-01-01
Are sediment quality guidelines (SQGs) adequately able to predict the presence or absence of chronic toxicity to sediment-dwelling organisms in field-collected sediments? Can SQGs predict effects resulting from the bioaccumulation of sediment-associated contaminants? Do SQGs define cause-and-effect relationships? Can they predict effects on organisms exposed in the field on the basis of amphipod mortality measured in the laboratory?These and other questions brought together 55 scientists from 8 countries for a Pellston Workshop convened by the Society of Environmental Toxicology and Chemistry (SETAC) in Fairmont, Montana, USA. In this book, these experts in ecology, ecotoxicology, engineering, environmental regulation, and risk assessment examine the scientific underpinnings of sediment quality guidelines and provide recommendations on the appropriate use of SQGs in the assessment and management of contaminated sediments.
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Pesticides reduce regional biodiversity of stream invertebrates
Beketov, Mikhail A.; Kefford, Ben J.; Schäfer, Ralf B.; Liess, Matthias
2013-01-01
The biodiversity crisis is one of the greatest challenges facing humanity, but our understanding of the drivers remains limited. Thus, after decades of studies and regulation efforts, it remains unknown whether to what degree and at what concentrations modern agricultural pesticides cause regional-scale species losses. We analyzed the effects of pesticides on the regional taxa richness of stream invertebrates in Europe (Germany and France) and Australia (southern Victoria). Pesticides caused statistically significant effects on both the species and family richness in both regions, with losses in taxa up to 42% of the recorded taxonomic pools. Furthermore, the effects in Europe were detected at concentrations that current legislation considers environmentally protective. Thus, the current ecological risk assessment of pesticides falls short of protecting biodiversity, and new approaches linking ecology and ecotoxicology are needed. PMID:23776226
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Ecotoxicity of naproxen and its phototransformation products.
Isidori, Marina; Lavorgna, Margherita; Nardelli, Angela; Parrella, Alfredo; Previtera, Lucio; Rubino, Maria
2005-09-15
The occurrence of pharmaceuticals in the environment is of great concern and only few data are available about the adverse effects of such molecules and their derivatives on non-target aquatic organisms. This study was designed to assess the toxic potential of Naproxen, a nonsteroidal anti-inflammatory, Naproxen Na, its freely water soluble sodium salt and their photoproducts in the aquatic environment. Bioassays were performed on algae, rotifers and microcrustaceans to assess acute and chronic toxicity. Furthermore, possible genotoxic effects of photoderivatives were investigated using SOS chromotest and Ames fluctuation test. The results showed that photoproducts were more toxic than the parent compounds both for acute and chronic values, while genotoxic and mutagenic effects were not found. These findings suggested the opportunity to consider derivatives in ecotoxicology assessment of drugs.
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Barra Caracciolo, Anna; Cardoni, Martina; Pescatore, Tanita; Patrolecco, Luisa
2017-07-01
The anionic surfactant sodium lauryl ether sulphate (SLES) is the main component of most commercial products used for soil conditioning in the excavation industry, in particular as lubricants for mechanized tunnelling. Its use during the excavation processes can result in either the subsequent possible re-use of the huge amount of soil debris as by-products (e.g. land covering) or its discharge as waste. Currently, there are neither SLES soil threshold limits in European legislation, nor comprehensive studies on the environmental risk for soil ecosystems in these exposure scenarios. In this context, the present paper reviews the available data on the intrinsic characteristics of persistence and the ecotoxicological effects of the anionic surfactant SLES. Although SLES is generally reported to be biodegradable in standard tests, with degradation rates between 7 h and 30 days, depending on the initial conditions, data on its biodegradation in environmental studies are quite scarce. Consequently, assessing SLES biodegradation rates in field conditions is crucial for evaluating if in residual concentrations (typically in the range 40-500 mg/kg in excavated soils) it can or not be a potential hazard for terrestrial and water organisms. Laboratory ecotoxicological tests pointed out detrimental effects of SLES for aquatic organisms, while data on the terrestrial species are rather poor so far and further studies at the expected environmental concentrations are necessary. Finally, the review reports the main analytical methods available for detecting anionic surfactants in solid matrices and the future research needed to improve knowledge on the possible environmental risks posed by the use of SLES in foaming agents for mechanized tunnelling. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Prioritization of pharmaceuticals based on risks to aquatic environments in Kazakhstan.
Aubakirova, Bakhyt; Beisenova, Raikhan; Boxall, Alistair Ba
2017-09-01
Over the last 20 years, there has been increasing interest in the occurrence, fate, effects, and risk of pharmaceuticals in the natural environment. However, we still have only limited or no data on ecotoxicological risks of many of the active pharmaceutical ingredients (APIs) currently in use. This is partly due to the fact that the environmental assessment of an API is an expensive, time-consuming, and complicated process. Prioritization methodologies, which aim to identify APIs of most concern in a particular situation, could therefore be invaluable in focusing experimental work on APIs that really matter. The majority of approaches for prioritizing APIs require annual pharmaceutical usage data. These methods cannot therefore be applied to countries, such as Kazakhstan, that have very limited data on API usage. The present paper therefore offers an approach for prioritizing APIs in surface waters in information-poor regions such as Kazakhstan. Initially data were collected on the number of products and active ingredients for different therapeutic classes in use in Kazakhstan and on the typical doses. These data were then used alongside simple exposure modeling approaches to estimate exposure indices for active ingredients (about 240 APIs) in surface waters in the country. Ecotoxicological effects data were obtained from the literature or predicted. Risk quotients were then calculated for each pharmaceutical based on the exposure and the substances were ranked in order of risk quotient. Highest exposure indices were obtained for benzylpenicillin, metronidazole, sulbactam, ceftriaxone, and sulfamethoxazole. The highest risk was estimated for amoxicillin, clarithromycin, azithromycin, ketoconazole, and benzylpenicillin. In the future, the approach could be employed in other regions where usage information is limited. Integr Environ Assess Manag 2017;13:832-839. © 2017 SETAC. © 2017 SETAC.
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Dagnino, Alessandro; Sforzini, Susanna; Dondero, Francesco; Fenoglio, Stefano; Bona, Elisa; Jensen, John; Viarengo, Aldo
2008-07-01
A new Expert Decision Support System (EDSS) that can integrate Triad data for assessing environmental risk and biological vulnerability at contaminated sites has been developed. Starting with ecosystem relevance, the EDSS assigns different weights to the results obtained from Triad disciplines. The following parameters have been employed: 1) chemical soil analyses (revealing the presence of potentially dangerous substances), 2) ecotoxicological bioassays (utilizing classical endpoints such as survival and reproduction rates), 3) biomarkers (showing sublethal pollutant effects), and 4) ecological parameters (assessing changes in community structure and functions). For each Triad discipline, the EDSS compares the data obtained at the studied field sites with reference values and calculates different 0-1 indexes (e.g., Chemical Risk Index, Ecotoxicological Risk Index, and Ecological Risk Index). The EDSS output consists of 3 indexes: 1) Environmental Risk index (EnvRI), quantifying the levels of biological damage at population-community level, 2) Biological Vulnerability Index (BVI), assessing the potential threats to biological equilibriums, and 3) Genotoxicity Index (GTI), screening genotoxicity effects. The EDSS has been applied in the integration of a battery of Triad data obtained during the European Union-funded Life Intervention in the Fraschetta Area (LINFA) project, which has been carried out in order to estimate the potential risk from soils of a highly anthropized area (Alessandria, Italy) mainly impacted by deposition of atmospheric pollutants. Results obtained during 4 seasonal sampling campaigns (2004-2005) show maximum values of EnvRI in sites A and B (characterized by industrial releases) and lower levels in site D (affected by vehicular traffic emissions). All 3 potentially polluted sites have shown high levels of BVI and GTI, suggesting a general change from reference conditions (site C).
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Acute embryo toxicity and teratogenicity of three potential biofuels also used as flavor or solvent.
Bluhm, Kerstin; Seiler, Thomas-Benjamin; Anders, Nico; Klankermayer, Jürgen; Schaeffer, Andreas; Hollert, Henner
2016-10-01
The demand for biofuels increases due to concerns regarding greenhouse gas emissions and depletion of fossil oil reserves. Many substances identified as potential biofuels are solvents or already used as flavors or fragrances. Although humans and the environment may be readily exposed little is known regarding their (eco)toxicological effects. In this study, the three potential biofuels ethyl levulinate (EL), 2-methyltetrahydrofuran (2-MTHF) and 2-methylfuran (2-MF) were investigated for their acute embryo toxicity and teratogenicity using the fish embryo toxicity (FET) test to identify unknown hazard potentials and to allow focusing further research on substances with low toxic potentials. In addition, two fossil fuels (diesel and gasoline) and an established biofuel (rapeseed oil methyl ester) were investigated as references. The FET test is widely accepted and used in (eco)toxicology. It was performed using the zebrafish Danio rerio, a model organism useful for the prediction of human teratogenicity. Testing revealed a higher acute toxicity for EL (LC50: 83mg/L) compared to 2-MTHF (LC50: 2980mg/L), 2-MF (LC50: 405mg/L) and water accommodated fractions of the reference fuels including gasoline (LC50: 244mg DOC/L). In addition, EL caused a statistically significant effect on head development resulting in elevated head lengths in zebrafish embryos. Results for EL reduce its likelihood of use as a biofuel since other substances with a lower toxic potential are available. The FET test applied at an early stage of development might be a useful tool to avoid further time and money requiring steps regarding research on unfavorable biofuels. Copyright © 2016 Elsevier B.V. All rights reserved.
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Baderna, Diego; Lomazzi, Eleonora; Pogliaghi, Alberto; Ciaccia, Gianluca; Lodi, Marco; Benfenati, Emilio
2015-07-01
Metals can pollute soils in both urban and rural areas with severe impacts on the health of humans, plants and animals living there. Information on metal toxicity is therefore important for ecotoxicology. This study investigated the phytotoxicity of different metals frequently found as pollutants in soils: arsenic, cadmium, chromium, lead, mercury, nickel and zinc. Cucumber (Cucumis sativus), sorghum (Sorghum saccharatum) and cress (Lepidium sativum) seeds were used as models for other plants used in human nutrition such as cereals, rice, fruits and vegetables. The 72-h germination rate and root elongations were selected as short-term ecotoxicological endpoints in seeds exposed to single metals and mixtures. Metals were spiked onto OECD standard soils in concentrations comparable to current Italian contamination threshold concentrations for residential and commercial soils. Arsenic, chromium, mercury and nickel were the most toxic metals in our experimental conditions, particularly to cress seeds (5.172, 152 and 255.4 mg/kg as 72 h IC50 for arsenic, mercury and nickel respectively). Italian limits were acceptable for plant protection only for exposure to each metal alone but not for the mixtures containing all the metals concentrations expected by their respective legislative threshold. The effects of the mixture were class-specific: trends were comparable in dicots but different in monocots. The response induced by the mixture at high concentrations differed from that theoretically obtainable by summing the effects of the individual metals. This might be due to partial antagonism of the metals in soil or to the formation of complexes between the metals, which reduce the bioavailability of the pollutants for plants. Copyright © 2015 Elsevier Inc. All rights reserved.
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Behavioural ecotoxicology, an “early warning” signal to assess environmental quality
2010-01-01
Background In this review, the position of behavioural ecotoxicology within the available means to assess the status of marine environments is described as filling the gap for the needed “early warning” signals. A few examples of studies performed since the 1960s are discussed to highlight the sensitivity of these approaches in investigating the effects of chemicals, including priority pollutants and emerging contaminants, relative to conventional toxicity tests measuring survival. Discussion The advantage of the behavioural response is due to the integration of biochemical and physiological processes that reflect changes at higher levels of organisation with ecological relevance. Avoidance often represents a behavioural symptom easily detected in many animals exposed to contaminants and would be a useful test to explore more widely. This rapid response would reflect a defence mechanism protective against further exposure and the potential development of more pronounced deleterious effects, whilst in some cases, escape could lead to the relocation of a species with negative consequences. An investigation of the avoidance behaviour of mud shrimp, Corophium volutator, along with the chemical analyses of sediments and amphipods to assess the quality of harbour sediments is summarised. The body burden of the amphipods was 1,000 times lower than the one associated with narcosis, emphasizing the sensitivity of this endpoint. The application of this acute toxicity test is briefly compared to additional work that involved intertidal mussels collected in the field. Conclusions Recent research undertaken with mud snails, Ilyanassa obsoleta, and harbour sediments confirmed the usefulness of the escape behaviour as an assessment tool. However, the limits of the state of knowledge regarding the fate of contaminants in species with the ability to metabolise contaminants is further discussed along with directions to be pursued to address questions arising from the reviewed literature. PMID:20614196
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Morales, Johnny E., E-mail: johnny.morales@lh.org.
Purpose: An experimental extrapolation technique is presented, which can be used to determine the relative output factors for very small x-ray fields using the Gafchromic EBT3 film. Methods: Relative output factors were measured for the Brainlab SRS cones ranging in diameters from 4 to 30 mm{sup 2} on a Novalis Trilogy linear accelerator with 6 MV SRS x-rays. The relative output factor was determined from an experimental reducing circular region of interest (ROI) extrapolation technique developed to remove the effects of volume averaging. This was achieved by scanning the EBT3 film measurements with a high scanning resolution of 1200 dpi.more » From the high resolution scans, the size of the circular regions of interest was varied to produce a plot of relative output factors versus area of analysis. The plot was then extrapolated to zero to determine the relative output factor corresponding to zero volume. Results: Results have shown that for a 4 mm field size, the extrapolated relative output factor was measured as a value of 0.651 ± 0.018 as compared to 0.639 ± 0.019 and 0.633 ± 0.021 for 0.5 and 1.0 mm diameter of analysis values, respectively. This showed a change in the relative output factors of 1.8% and 2.8% at these comparative regions of interest sizes. In comparison, the 25 mm cone had negligible differences in the measured output factor between zero extrapolation, 0.5 and 1.0 mm diameter ROIs, respectively. Conclusions: This work shows that for very small fields such as 4.0 mm cone sizes, a measureable difference can be seen in the relative output factor based on the circular ROI and the size of the area of analysis using radiochromic film dosimetry. The authors recommend to scan the Gafchromic EBT3 film at a resolution of 1200 dpi for cone sizes less than 7.5 mm and to utilize an extrapolation technique for the output factor measurements of very small field dosimetry.« less
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Molecular Endpoints and Mixtures of EDCs in Fish
Microarray technology is a relatively novel tool in ecotoxicology and is beginning to be used for exposure and/or hazard characterization for ecological risk assessment. To develop a basis for this type of analysis, fathead minnows (Pimephales promelas) were treated with two bin...
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Small fish species with an asynchronous pattern of gonad development and reproduction are commonly used test organisms in aquatic ecotoxicology and more recently in ecotoxicogenomics. This study applies coordinated histological examination and fathead minnow oligonucleotide micr...
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Anaerobic biochemical reactors (BCRs) are useful for removing metals from mining-impacted water at remote sites. Removal processes include sorption and precipitation of metal sulfides, carbonates, and hydroxides. A question of interest is whether BCRs remove aquatic toxicity. ...
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Development and application of transcriptomics-based gene classifiers for ecotoxicological applications lag far behind those of human biomedical science. Many such classifiers discovered thus far lack vigorous statistical and experimental validations, with their stability and rel...
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This letter to the editor that does not have an abstract. It explains mode of action in aquatic toxicology, and rebuts comments about our mode of action classification caused by confusion of the commenter.
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Ecology and ecotoxicology share common goals - tracing and quantifying material flux in the environment. Bridging these disciplines is challenging because their practitioners have slightly different methods, terminologies and objectives. For example, ecologists strive to identify...
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AN ECOLOGICAL PERSPECTIVE OF GENOMICS: PROBLEM FORMULATION
n March 2001, an International Council of Chemical Associates sponsored workshop on genomics was held in Orlando, Florida. The objective of the workshop was to review the state-of-the science in the application of genomic technologies in toxicology, ecotoxicology, and molecular e...
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A RE-EXAMINATION OF VARIATION ASSOCIATED WITH ENVIRONMENTALLY STRESSED ORGANISMS
Variation is an essential feature of biological systems. Populations adapt to dynamic environments, in part, because of this variation. In this review, we re-examine phenotypic variation, especially in organisms living in polluted environments. A recent goal of ecotoxicology is t...
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Assessment Tools for the Evaluation of Risk
ASTER (Assessment Tools for the Evaluation of Risk) was developed by the U.S. EPA Mid-Continent Ecology Division, Duluth, MN to assist regulators in performing ecological risk assessments. ASTER is an integration of the ECOTOXicology Database (ECOTOX; Regulatory Aspects on the Use of Fish Embryos in Environmental Toxicology
Animal alternative tests are gaining consideration in an array of environmental sciences, particularly as they relate to sound management of chemicals and wastewater discharges. The ILSI Health and Environmental Sciences Institute and the European Centre for Ecotoxicology and To...
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Establishing Adverse Outcome Pathways of Thyroid Hormone Disruption in an Amphibian Model
The Adverse Outcome Pathway (AOP) provides a framework for understanding the relevance of toxicology data in ecotoxicological hazard assessments. The AOP concept can be applied to many toxicological pathways including thyroid hormone disruption. Thyroid hormones play a critical r...
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Infrared length scale and extrapolations for the no-core shell model
Wendt, K. A.; Forssén, C.; Papenbrock, T.; ...
2015-06-03
In this paper, we precisely determine the infrared (IR) length scale of the no-core shell model (NCSM). In the NCSM, the A-body Hilbert space is truncated by the total energy, and the IR length can be determined by equating the intrinsic kinetic energy of A nucleons in the NCSM space to that of A nucleons in a 3(A-1)-dimensional hyper-radial well with a Dirichlet boundary condition for the hyper radius. We demonstrate that this procedure indeed yields a very precise IR length by performing large-scale NCSM calculations for 6Li. We apply our result and perform accurate IR extrapolations for bound statesmore » of 4He, 6He, 6Li, and 7Li. Finally, we also attempt to extrapolate NCSM results for 10B and 16O with bare interactions from chiral effective field theory over tens of MeV.« less
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Käkinen, Aleksandr; Bondarenko, Olesja; Ivask, Angela; Kahru, Anne
2011-01-01
The analysis of (bio)available copper in complex environmental settings, including biological test media, is a challenging task. In this study, we demonstrated the potential of a recombinant Pseudomonas fluorescens-based biosensor for bioavailability analysis of CuSO4 and CuO nanoparticles (nano-CuO) in seventeen different ecotoxicological and microbiologial test media. In parallel, free Cu in these test media was analysed using Cu-ion selective electrode (Cu-ISE). In the case of CuSO4, both free and bioavailable Cu decreased greatly with increasing concentration of organics and phosphates in the tested media. A good correlation between free and bioavailable Cu was observed (r = 0.854, p < 0.01) indicating that the free Cu content in biological test media may be a reasonably good predictor for the toxicity of CuSO4. As a proof, it was demonstrated that when eleven EC50 values for CuSO4 from different organisms in different test media were normalized for the free Cu in these media, the difference in these EC50 values was decreased from 4 to 1.8 orders of magnitude. Thus, toxicity of CuSO4 to these organisms was attributed to the properties of the test media rather than to inherent differences in sensitivity between the test organisms. Differently from CuSO4, the amount of free and bioavailable Cu in nano-CuO spiked media was not significantly correlated with the concentration of organics in the test media. Thus, the speciation of nano-CuO in toxicological test systems was not only determined by the complexation of Cu ions but also by differential dissolution of nano-CuO in different test conditions leading to a new speciation equilibrium. In addition, a substantial fraction of nano-CuO that was not detectable by Cu-ISE (i.e., not present as free Cu-ions) was bioavailable to Cu-biosensor bacteria. Thus, in environmental hazard analysis of (nano) particulate materials, biosensor analysis may be more informative than other analytical techniques. Our results demonstrate that bacterial Cu-biosensors either in combination with other analytical/speciation techniques or on their own, may serve as a rapid (eco)toxicological screening method. PMID:22346655
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Line-of-sight extrapolation noise in dust polarization
NASA Astrophysics Data System (ADS)
Poh, Jason; Dodelson, Scott
2017-05-01
The B-modes of polarization at frequencies ranging from 50-1000 GHz are produced by Galactic dust, lensing of primordial E-modes in the cosmic microwave background (CMB) by intervening large scale structure, and possibly by primordial B-modes in the CMB imprinted by gravitational waves produced during inflation. The conventional method used to separate the dust component of the signal is to assume that the signal at high frequencies (e.g. 350 GHz) is due solely to dust and then extrapolate the signal down to a lower frequency (e.g. 150 GHz) using the measured scaling of the polarized dust signal amplitude with frequency. For typical Galactic thermal dust temperatures of ˜20 K , these frequencies are not fully in the Rayleigh-Jeans limit. Therefore, deviations in the dust cloud temperatures from cloud to cloud will lead to different scaling factors for clouds of different temperatures. Hence, when multiple clouds of different temperatures and polarization angles contribute to the integrated line-of-sight polarization signal, the relative contribution of individual clouds to the integrated signal can change between frequencies. This can cause the integrated signal to be decorrelated in both amplitude and direction when extrapolating in frequency. Here we carry out a Monte Carlo analysis on the impact of this line-of-sight extrapolation noise on a greybody dust model consistent with Planck and Pan-STARRS observations, enabling us to quantify its effect. Using results from the Planck experiment, we find that this effect is small, more than an order of magnitude smaller than the current uncertainties. However, line-of-sight extrapolation noise may be a significant source of uncertainty in future low-noise primordial B-mode experiments. Scaling from Planck results, we find that accounting for this uncertainty becomes potentially important when experiments are sensitive to primordial B-mode signals with amplitude r ≲0.0015 in the greybody dust models considered in this paper.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Fang, Jun; Wang, Han, E-mail: wang-han@iapcm.ac.cn; CAEP Software Center for High Performance Numerical Simulation, Beijing
2016-06-28
Wavefunction extrapolation greatly reduces the number of self-consistent field (SCF) iterations and thus the overall computational cost of Born-Oppenheimer molecular dynamics (BOMD) that is based on the Kohn–Sham density functional theory. Going against the intuition that the higher order of extrapolation possesses a better accuracy, we demonstrate, from both theoretical and numerical perspectives, that the extrapolation accuracy firstly increases and then decreases with respect to the order, and an optimal extrapolation order in terms of minimal number of SCF iterations always exists. We also prove that the optimal order tends to be larger when using larger MD time steps ormore » more strict SCF convergence criteria. By example BOMD simulations of a solid copper system, we show that the optimal extrapolation order covers a broad range when varying the MD time step or the SCF convergence criterion. Therefore, we suggest the necessity for BOMD simulation packages to open the user interface and to provide more choices on the extrapolation order. Another factor that may influence the extrapolation accuracy is the alignment scheme that eliminates the discontinuity in the wavefunctions with respect to the atomic or cell variables. We prove the equivalence between the two existing schemes, thus the implementation of either of them does not lead to essential difference in the extrapolation accuracy.« less
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Raybould, Alan; Caron-Lormier, Geoffrey; Bohan, David A
2011-06-08
Cost-effective and rigorous risk assessments for chemicals may be based on hazard quotients (HQs): the ratio of a measure of exposure to a substance and a measure of the effect of that substance. HQs have been used for many years in ecological risk assessments for the use of synthetic pesticides in agriculture, and methods for calculating pesticide HQs have been adapted for use with transgenic crops. This paper describes how laboratory methods for assessing the ecotoxicological effects of synthetic pesticides have been modified for the measurement of effects of insecticidal proteins, and how these effect measures are combined with exposure estimates to derive HQs for assessing the ecological risks from the cultivation of insect-resistant transgenic crops. The potential for ecological modeling to inform the design of laboratory effects tests for insecticidal proteins is also discussed.
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UV testing of solar cells: Effects of antireflective coating, prior irradiation, and UV source
NASA Technical Reports Server (NTRS)
Meulenberg, A.
1993-01-01
Short-circuit current degradation of electron irradiated double-layer antireflective-coated cells after 3000 hours ultraviolet (UV) exposure exceeds 3 percent; extrapolation of the data to 10(exp 5) hours (11.4 yrs.) gives a degradation that exceeds 10 percent. Significant qualitative and quantitative differences in degradation were observed in cells with double- and single-layer antireflective coatings. The effects of UV-source age were observed and corrections were made to the data. An additional degradation mechanism was identified that occurs only in previously electron-irradiated solar cells since identical unirradiated cells degrade to only 6 +/- 3 percent when extrapolated 10(exp 5) hours of UV illumination.
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Antunes, Sara C; Castro, Bruno B; Moreira, Cláudia; Gonçalves, Fernando; Pereira, Ruth
2013-02-01
As a part of the Ecological Risk Assessment of a deactivated uranium mining area (Cunha Baixa), the aim of this study was to assess the drivers of litter arthropod community (ecological line of evidence) inhabiting soils with different degrees of contamination. Litter arthropods were collected in the mining area using a total of 70 pitfall traps, in the spring and autumn of 2004. Unlike information previously collected in the chemical and ecotoxicological lines of evidence, we found no clear evidence of impacts of soil contamination on the edaphic arthropod assemblage. Multivariate analyses were unable to extract relevant environmental gradients related to contamination, as most of the sites shared the same taxa overall. Given the consistency of the chemical and ecotoxicological lines of evidence, we must conclude that the litter arthropod assemblage underestimated the impacts of contamination in this abandoned mining area. In part, this could be due to the uncertainty caused by confounding factors that affect the litter arthropod community in the area. Nevertheless, despite the overall lack of responsiveness of the epigeic arthropod community data, a few taxa were negatively correlated with metal concentrations (Clubionidae and Staphylinidae), while Pseudoscorpionida were associated with the toxicological profile of the sites. These evidences suggest that community-level approaches with other animal and plant assemblages are necessary to reduce uncertainty relatively to the assessment of risks in higher evaluation tiers in the Cunha Baixa mine area. Copyright © 2012 Elsevier Inc. All rights reserved.
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Bai, Junhong; Lu, Qiongqiong; Zhao, Qingqing; Wang, Junjing; Gao, Zhaoqin; Zhang, Guangliang
2015-01-01
Soil profiles were collected at a depth of 30 cm in ditch wetlands (DWs), riverine wetlands (RiWs) and reclaimed wetlands (ReWs) along a 100-year chronosequence of reclamation in the Pearl River Delta. In total, 16 OCPs were measured to investigate the effects of wetland reclamation and reclamation history on OCP levels. Our results showed that average ∑DDTs, HCB, MXC, and ∑OCPs were higher in surface soils of DWs compared to RiWs and ReWs. Both D30 and D20 soils contained the highest ∑OCP levels, followed by D40 and D100 soils; lower ∑OCP levels occurred in D10 soils. Higher ∑OCP levels were observed in the younger RiWs than in the older ones, and surface soils exhibited higher ∑OCP concentrations in the older ReWs compared with younger ReWs. The predominant percentages of γ-HCH in ∑HCHs (>42%) and aldrin in ∑DRINs (>46%) in most samples reflected the recent use of lindane and aldrin. The presence of dominant DDT isomers (p,p’-DDE and p,p’-DDD) indicated the historical input of DDT and significant aerobic degradation of the compound. Generally, DW soils had a higher ecotoxicological risk of OCPs than RiW and ReW soils, and the top 30 cm soils had higher ecotoxicological risks of HCHs than of DDTs. PMID:26633149
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NASA Astrophysics Data System (ADS)
Bai, Junhong; Lu, Qiongqiong; Zhao, Qingqing; Wang, Junjing; Gao, Zhaoqin; Zhang, Guangliang
2015-12-01
Soil profiles were collected at a depth of 30 cm in ditch wetlands (DWs), riverine wetlands (RiWs) and reclaimed wetlands (ReWs) along a 100-year chronosequence of reclamation in the Pearl River Delta. In total, 16 OCPs were measured to investigate the effects of wetland reclamation and reclamation history on OCP levels. Our results showed that average ∑DDTs, HCB, MXC, and ∑OCPs were higher in surface soils of DWs compared to RiWs and ReWs. Both D30 and D20 soils contained the highest ∑OCP levels, followed by D40 and D100 soils; lower ∑OCP levels occurred in D10 soils. Higher ∑OCP levels were observed in the younger RiWs than in the older ones, and surface soils exhibited higher ∑OCP concentrations in the older ReWs compared with younger ReWs. The predominant percentages of γ-HCH in ∑HCHs (>42%) and aldrin in ∑DRINs (>46%) in most samples reflected the recent use of lindane and aldrin. The presence of dominant DDT isomers (p,p’-DDE and p,p’-DDD) indicated the historical input of DDT and significant aerobic degradation of the compound. Generally, DW soils had a higher ecotoxicological risk of OCPs than RiW and ReW soils, and the top 30 cm soils had higher ecotoxicological risks of HCHs than of DDTs.
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Modeling of facade leaching in urban catchments
NASA Astrophysics Data System (ADS)
Coutu, S.; Del Giudice, D.; Rossi, L.; Barry, D. A.
2012-12-01
Building facades are protected from microbial attack by incorporation of biocides within them. Flow over facades leaches these biocides and transports them to the urban environment. A parsimonious water quantity/quality model applicable for engineered urban watersheds was developed to compute biocide release from facades and their transport at the urban basin scale. The model couples two lumped submodels applicable at the basin scale, and a local model of biocide leaching at the facade scale. For the facade leaching, an existing model applicable at the individual wall scale was utilized. The two lumped models describe urban hydrodynamics and leachate transport. The integrated model allows prediction of biocide concentrations in urban rivers. It was applied to a 15 km2urban hydrosystem in western Switzerland, the Vuachère river basin, to study three facade biocides (terbutryn, carbendazim, diuron). The water quality simulated by the model matched well most of the pollutographs at the outlet of the Vuachère watershed. The model was then used to estimate possible ecotoxicological impacts of facade leachates. To this end, exceedance probabilities and cumulative pollutant loads from the catchment were estimated. Results showed that the considered biocides rarely exceeded the relevant predicted no-effect concentrations for the riverine system. Despite the heterogeneities and complexity of (engineered) urban catchments, the model application demonstrated that a computationally "light" model can be employed to simulate the hydrograph and pollutograph response within them. It thus allows catchment-scale assessment of the potential ecotoxicological impact of biocides on receiving waters.
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Ecotoxicological impact of highway runoff using brown trout (Salmo trutta L.) as an indicator model.
Meland, Sondre; Salbu, Brit; Rosseland, Bjørn Olav
2010-03-01
The ecotoxicological impact of highway runoff on brown trout (Salmo trutta L.) was studied in an in situ experiment consisting of four 24 h simulated runoff episodes. Fish were maintained in 5 tanks and exposed to highway runoff from a sedimentation pond close to E6 outside the city of Oslo, Norway. The tanks had the following contaminant loadings during the episodes: stream water (control), pond inlet, pond outlet, pond inlet + stream water and pond outlet + stream water. Opposite to road salt and compared to earlier findings, the first two episodes had rather low concentrations of trace metals, hydrocarbons and polycyclic aromatic hydrocarbons. A heavy rainfall before episode 3 increased the concentrations of all the contaminants except road salt which was diluted. In addition, lowered oxygen levels led to hypoxic conditions. Overall the fish exposed to highway runoff had, compared to the control fish, higher concentrations of trace metals in gills and liver, increased activity of the antioxidant defense system represented by superoxide dismutase, catalase and metallothionein, problems with the regulation of plasma Cl and Na, as well as increased levels of blood glucose and pCO(2). Finally, this seemed to affect the metabolism of the fish through reduced condition factor. The observed effects were likely caused by multiple stressors and not by a single contaminant. The sedimentation pond clearly reduced the toxicity of the highway runoff. But even in the least polluted exposure tank (pond outlet + stream water) signs of physiological disturbances were evident.
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Alvarenga, Paula; Mourinha, Clarisse; Farto, Márcia; Palma, Patrícia; Sengo, Joana; Morais, Marie-Christine; Cunha-Queda, Cristina
2016-04-01
This study aimed to assess the potential impact on soil porewater, surface and groundwater from the beneficial application of organic wastes to soil, using their eluates and acute bioassays with aquatic organisms and plants: luminescence inhibition of Vibrio fischeri (15 and 30 min), Daphnia magna immobilization (48 h), Thamnocephalus platyurus survival (24 h), and seed germination of Lolium perenne (7 d) and Lactuca sativa (5 d). Some organic wastes' eluates promoted high toxic responses, but that toxicity could not be predicted by their chemical characterization, which is compulsory by regulatory documents. In fact, when organisms were exposed to the water-extractable chemical compounds of the organic wastes, the toxic responses were more connected to the degree of stabilization of the organic wastes, or to the treatment used to achieve that stabilization, than to their contaminant load. That is why the environmental risk assessment of the use of organic wastes as soil amendments should integrate bioassays with eluates, in order to correctly evaluate the effects of the most bioavailable fraction of all the chemical compounds, which can be difficult to predict from the characterization required in regulatory documents. According to our results, some rapid and standardized acute bioassays can be suggested to integrate a Tier 1 ecotoxicological evaluation of organic wastes with potential to be land applied, namely luminescence inhibition of V. fischeri, D. magna immobilization, and the germination of L. perenne and L. sativa. Copyright © 2015 Elsevier Inc. All rights reserved.
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Ranjbar Jafarabadi, Ali; Riyahi Bakhtiari, Alireza; Shadmehri Toosi, Amirhossein
2017-11-01
The concentration and spatial distribution along with ecotoxicological risk of 30 polycyclic aromatic hydrocarbons were investigated in the reef surface sediments (RSSs) and coastal seawater (CSW) of ten coral Islands from the Persian Gulf, Iran, in January 2015. For all sampling sites, assessment of ecological risk was undertaken using several approaches. Mean concentration of ∑30PAHs varied between 70 and 884ngL -l with an overall mean value of 464ngL -l in the CSW, while the RSS ranged from 274 to 1098ngg -1 dw with a total average of 619ngg -1 dw. The results showed a gradient in PAH concentration and toxicity estimates from the northern Hormoz site increasing to the eastern Kharg site. Most of the toxicity estimates were in the moderate range or less than risk values for damage to the marine environment. The calculated Dermal Hazard Quotient (HQs), the sum of HQs (HI) and other cancer risk values of most compounds were less than safety values at most sites. It means that the possibility of negative effects of PAHs via dermal absorption from sediments for children and adults is low. Some sampling sites studied have already been impacted with hazardous pollutants for an extended period of time and evidence from this investigation demonstrates that mixtures of PAHs may be carcinogenic to humans, especially in the western part of the Gulf. Copyright © 2017 Elsevier Inc. All rights reserved.
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3. A Closed Aquatic System for Space and Earth Application
NASA Astrophysics Data System (ADS)
Slenzka, K.; Duenne, M.; Jastorff, B.; Ranke, J.; Schirmer, M.
Increased durations in space travel as well as living in extreme environments are requiring reliable life support systems in general and bioregenerative ones in detail. Waste water management, air revitalization and food production are obviously center goals in this research, however, in addition a potential influence by chemicals, drugs etc. released to the closed environment must be considered. On this basis ecotoxicological data become more and more important for CELSS (Closed Ecological Life Support System) development and performance. The experiences gained during the last years in our research group lead to the development of an aquatic habitat, called AquaHab (formerly CBRU), which is a closed, self-sustaining system with a total water volume of 9 liters. In the frame program of a R&D project funded by the state of Bremen and OHB System, AquaHab is under adaptation to become an ecotoxicological research unit containing for example Japanese Medaka or Zebra Fish, amphipods, water snails and water plants. Test runs were standardized and analytical methods were developed. Beside general biological and water chemical parameters, activity measurements of biotransforming enzymes (G6PDH, CytP450-Oxidase, Peroxidase) and cell viability tests as well as residual analysis of the applied substance and respective metabolites were selected as evaluation criteria. In a first series of tests low doses effects of TBT (Tributyltin, 0.1 to 20 μgTBT/l nominal concentration) were analyzed. The AquaHab and data obtained for applied environmental risk assessment will be presented at the assembly.
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Hennebert, Pierre
2018-04-01
Different ecotoxicological test batteries and concentration limits have been proposed to assess the hazard property (HP) HP 14 'Ecotoxic' for waste in the European Union and its member states. In test batteries, if the concentration of waste in the culture/dilution medium producing 50% of inhibitory biological effect in one or more test(s) is below the concentration limit of the test, the waste is classified as hazardous. A summarized review of the test batteries proposed since 1998 is presented. The last proposed test battery uses seven aquatic and terrestrial species with standardized methods, but with options and uniform concentration limits of 10% of waste eluate or solid waste in the culture/dilution medium. No attempt was made to match this hazard assessment with the classification made in the European List of Waste (LoW). The aim of this paper is to propose for the same test battery (reduced to 6 tests without options) concentration limits that match with the European List of Waste. This list was taken as reference (despite the fact that waste can be hazardous for other properties than the most frequent HP 14, and its partly political nature for some opinions). The concentration limits (CLs) for tests are the concentrations producing the highest ecotoxicological effects for each test observed in a non-hazardous waste set. Data from Germany, France and Belgium (from in total 5 different sources from 2009 to 2016) with the above-mentioned test battery (without options) were gathered for 81 samples, being the largest set ever published. In total, ten non-hazardous (NH) waste samples (as defined by the LoW and for most of them checked by chemical composition) were used to establish CLs. These CLs were then applied to 13 hazardous (H) waste by the LoW, and all were classified as hazardous. The matching of the resulting classification with the LoW is convincing. For the 58 'mirror entries' in the LoW (hazardous or not depending of the presence of hazardous substances), 37 were classified H (64%) and 21 were classified NH (36%). These concentration limits can be refined with the method proposed here, as soon as additional data of NH waste (by list and by composition) are available. The test battery (without options) and the concentration limits (in percent of waste in the culture/dilution medium) proposed are the following: A waste is hazardous for HP 14 'Ecotoxic' if the concentration of waste (eluate or solid) in the culture/dilution medium producing 50% of biological effect relative to the control EC 50 -30 min of Vibrio fischeri (EN ISO 11348-3) is lower than 15.8%, or if the EC 50 -72 h of Pseudokirchneriella subcapitata (EN ISO 8692) is lower than 7.03%, or if the EC 50 -48 h of Daphnia magna (EN ISO 6341) is lower than 7.95%, or if the EC 50 -6h of Arthrobacter globiformis (ISO 18187) is lower than 2.25%, or if the EC 50 -14d of Brassica rapa (EN ISO 11269-2) is lower than 13.7%, or if the EC 50 -48 h of Eisenia fetida avoidance test (ISO 17512-1) is lower than 3.75%. These CLs range between 2% and 16%, which is in line with the typically 10% concentration proposed without validation. To fix regulatory concentration limits, the regulators can use these CLs and the uncertainty of the ecotoxicological tests (standard deviation of inter-laboratory reproducibility typically of 25% of the mean, as published in the standards). Classification of waste for HP 14 with these tests and concentration limits will agree with the European List of Waste. Copyright © 2017 Elsevier Ltd. All rights reserved.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Pais-Costa, Antonia Juliana; Acevedo, Pelayo; Marques, João Carlos
Post-exposure bioassays are used in environmental assessment as a cost-effective tool, but the effects of organism's recovery after exposure to pollutant has not yet been addressed in detail. The recoveries of post-exposure feeding rates after being exposed to two sublethal concentrations of cadmium during two different exposure periods (48 h and 96 h) were evaluated under laboratory conditions using the estuarine isopod Cyathura carinata. Results showed that feeding depression was a stable endpoint up to 24 h after cadmium exposure, which is useful for ecotoxicological bioassays. - Highlights: • We studied recovery of post-exposure feeding rates 48–96 h after cadmiummore » exposure. • The assay is based on the isopod Cyathura carinata. • Post-exposure feeding inhibition is a stable sublethal endpoint.« less
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Extrapolating bound state data of anions into the metastable domain
NASA Astrophysics Data System (ADS)
Feuerbacher, Sven; Sommerfeld, Thomas; Cederbaum, Lorenz S.
2004-10-01
Computing energies of electronically metastable resonance states is still a great challenge. Both scattering techniques and quantum chemistry based L2 methods are very time consuming. Here we investigate two more economical extrapolation methods. Extrapolating bound states energies into the metastable region using increased nuclear charges has been suggested almost 20 years ago. We critically evaluate this attractive technique employing our complex absorbing potential/Green's function method that allows us to follow a bound state into the continuum. Using the 2Πg resonance of N2- and the 2Πu resonance of CO2- as examples, we found that the extrapolation works suprisingly well. The second extrapolation method involves increasing of bond lengths until the sought resonance becomes stable. The keystone is to extrapolate the attachment energy and not the total energy of the system. This method has the great advantage that the whole potential energy curve is obtained with quite good accuracy by the extrapolation. Limitations of the two techniques are discussed.
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Beresford, Nicola; Baynes, Alice; Kanda, Rakesh; Mills, Matthew R.; Arias-Salazar, Karla; Collins, Terrence J.; Jobling, Susan
2016-01-01
Endocrine Disrupting Compounds pose a substantial risk to the aquatic environment. Ethinylestradiol (EE2) and estrone (E1) have recently been included in a watch list of environmental pollutants under the European Water Framework Directive. Municipal wastewater treatment plants are major contributors to the estrogenic potency of surface waters. Much of the estrogenic potency of wastewater treatment plant (WWTP) effluents can be attributed to the discharge of steroid estrogens including estradiol (E2), EE2 and E1 due to incomplete removal of these substances at the treatment plant. An evaluation of the efficacy of wastewater treatment processes requires the quantitative determination of individual substances most often undertaken using chemical analysis methods. Most frequently used methods include Gas Chromatography-Mass Spectrometry (GCMS/MS) or Liquid Chromatography-Mass Spectrometry (LCMS/MS) using multiple reaction monitoring (MRM). Although very useful for regulatory purposes, targeted chemical analysis can only provide data on the compounds (and specific metabolites) monitored. Ecotoxicology methods additionally ensure that any by-products produced or unknown estrogenic compounds present are also assessed via measurement of their biological activity. A number of in vitro bioassays including the Yeast Estrogen Screen (YES) are available to measure the estrogenic activity of wastewater samples. Chemical analysis in conjunction with in vivo and in vitro bioassays provides a useful toolbox for assessment of the efficacy and suitability of wastewater treatment processes with respect to estrogenic endocrine disrupting compounds. This paper utilizes a battery of chemical and ecotoxicology tests to assess conventional, advanced and emerging wastewater treatment processes in laboratory and field studies. PMID:27684328
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Pérez, Sara; Fernández, Nuria; Ribeiro, Pedro A
2016-05-01
The use of three limpet species, Patella vulgata Linnaeus, 1758, Patella depressa Pennant, 1777 and Patella ulyssiponensis Gmelin, 1791 as model organisms in marine ecotoxicology has been evaluated. Initial laboratory experiments were aimed to standardize a biological test with embryos and larvae of Patella spp, establishing the percentage of normal trochophore larvae as endpoint. Before conducting in vitro fertilization, oocytes must be maturated artificially by incubation in an alkaline solution; therefore, alkalinizing agent, pH and time of eggs alkalinization were evaluated. Moreover, time of sperm activation, optimum sperm and oocytes concentration during fertilization, gamete contact time, use of stirring during the fertilization, egg concentration and incubation temperature were examined. Minimum sample size per treatment was also estimated. Exposure of oocytes for 10min to FSW alkalinized with NH4OH at pH 9.0, the use of undiluted sperm pre-activated during 45min and a concentration of 200 oocytesmL(-1), a gamete-contact time of 180min and egg incubation at 18°C during 24h at a concentration of 80 eggsmL(-1) were the conditions allowing maximal embryo-larval development success. With an error of 0.05, a sampling size ≥320 allows a 95% confidence in the estimate. This Patella spp. acute bioassay fulfills a number of important a priori requirements to be used in ecotoxicological studies. Nevertheless, in vitro fertilization requires considerable handling, which may lead to failure in fecundation. Such difficulties are also addressed, in order to facilitate the routine use of this protocol by other laboratories. Copyright © 2016 Elsevier Inc. All rights reserved.
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Martins, Samantha Eslava; Bianchini, Adalto
2011-07-01
The current status of toxicological tests performed with Brazilian native species was evaluated through a survey of the scientific data available in the literature. The information gathered was processed and an electronic toxicology database (http://www.inct-ta.furg.br/bd_toxicologico.php) was generated. This database provides valuable information for researchers to select sensitive and tolerant aquatic species to a large variety of aquatic pollutants. Furthermore, the toxicology database allows researchers to select species representative of an ecosystem of interest. Analysis of the toxicology database showed that ecotoxicological assays have significantly improved in Brazil over the last decade, in spite of the still relatively low number of tests performed and the restricted number of native species tested. This is because most of the research is developed in a few laboratories concentrated in certain regions of Brazil, especially in Southern and Southeast regions. Considering the extremely rich biodiversity and the large variety of aquatic ecosystems in Brazil, this finding points to the urgent need for the development of ecotoxicological studies with other groups of aquatic animals, such as insects, foraminifera, cnidarians, worms, amphibians, among others. This would help to derive more realistic water quality criteria (WQC) values, which would better protect the different aquatic ecosystems in Brazil. Finally, the toxicology database generated presents solid and science based information, which can encourage and drive the Environmental Regulatory Agencies in Brazil to derive WQC based on native species. In this context, the present paper discusses the historical evolution of ecotoxicological studies in Brazil, and how they have contributed to the improvement of the Brazilian Federal and Regional regulations for environment.
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The potential risks of nanomaterials: a review carried out for ECETOC
Borm, Paul JA; Robbins, David; Haubold, Stephan; Kuhlbusch, Thomas; Fissan, Heinz; Donaldson, Ken; Schins, Roel; Stone, Vicki; Kreyling, Wolfgang; Lademann, Jurgen; Krutmann, Jean; Warheit, David; Oberdorster, Eva
2006-01-01
During the last few years, research on toxicologically relevant properties of engineered nanoparticles has increased tremendously. A number of international research projects and additional activities are ongoing in the EU and the US, nourishing the expectation that more relevant technical and toxicological data will be published. Their widespread use allows for potential exposure to engineered nanoparticles during the whole lifecycle of a variety of products. When looking at possible exposure routes for manufactured Nanoparticles, inhalation, dermal and oral exposure are the most obvious, depending on the type of product in which Nanoparticles are used. This review shows that (1) Nanoparticles can deposit in the respiratory tract after inhalation. For a number of nanoparticles, oxidative stress-related inflammatory reactions have been observed. Tumour-related effects have only been observed in rats, and might be related to overload conditions. There are also a few reports that indicate uptake of nanoparticles in the brain via the olfactory epithelium. Nanoparticle translocation into the systemic circulation may occur after inhalation but conflicting evidence is present on the extent of translocation. These findings urge the need for additional studies to further elucidate these findings and to characterize the physiological impact. (2) There is currently little evidence from skin penetration studies that dermal applications of metal oxide nanoparticles used in sunscreens lead to systemic exposure. However, the question has been raised whether the usual testing with healthy, intact skin will be sufficient. (3) Uptake of nanoparticles in the gastrointestinal tract after oral uptake is a known phenomenon, of which use is intentionally made in the design of food and pharmacological components. Finally, this review indicates that only few specific nanoparticles have been investigated in a limited number of test systems and extrapolation of this data to other materials is not possible. Air pollution studies have generated indirect evidence for the role of combustion derived nanoparticles (CDNP) in driving adverse health effects in susceptible groups. Experimental studies with some bulk nanoparticles (carbon black, titanium dioxide, iron oxides) that have been used for decades suggest various adverse effects. However, engineered nanomaterials with new chemical and physical properties are being produced constantly and the toxicity of these is unknown. Therefore, despite the existing database on nanoparticles, no blanket statements about human toxicity can be given at this time. In addition, limited ecotoxicological data for nanomaterials precludes a systematic assessment of the impact of Nanoparticles on ecosystems. PMID:16907977
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There are several greener methods exist to synthesize zero–valent iron nanoparticles (nZVI) using different bio-based reducing agents. Although their useful properties in degradation of organic dyes, chlorinated organics, or arsenic have been described earlier, their characteriza...
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NEW NEPHRON DEVELOPMENT IN FISH FROM POLLUTED WATERS: A POSSIBLE BIOMARKER
Recent evidence has shown that fish have the ability to develop new nephrons following renal injury. This study evaluated the usefulness of quantifying developing nephrons in mature fish as an ecotoxicological assessment tool. Histological sections of kidney were prepared from At...
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Ecological risk assessors face increasing demands to assess more chemicals, with greater speed and accuracy, and to do so using fewer resources and experimental animals. New approaches in biological and computational sciences are being developed to generate mechanistic informatio...
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Ecological risk assessors face increasing demands to assess more chemicals, with greater speed and accuracy, and to do so using fewer resources and experimental animals. New approaches in biological and computational sciences may be able to generate mechanistic information that ...
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Systems biology, adverse outcome pathways, and ecotoxicology in the 21st century
While many definitions of systems biology exist, the majority of these contain most (if not all) of the following elements: global measurements of biological molecules to the extent technically feasible, dynamic measurements of key biological molecules to establish quantitative r...
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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
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Bringing the fathead minnow (Pimephales promelas) into the genomic era
The fathead minnow (Pimephales promelas) is a well-established ecotoxicological model organism that has been widely used for regulatory ecotoxicity testing and research for over a half century. Throughout this time, a lot of knowledge has been gained about the fathead minnow&rsqu...
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Ecological Realism of U.S. EPA Experimental Stream Facility Studies
The USEPA’s Experimental Stream Facility (ESF) conducts meso-scale ecotoxicology studies that account for both structural and functional responses of whole stream communities to contaminants or other stressors. The 16 mesocosms of ESF are indoors and consist of a tiled run sectio...
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Bringing the fathead minnow into the genomic era
The fathead minnow is a well-established ecotoxicological model organism that has been widely used for regulatory ecotoxicity testing and research for over a half century. While a large amount of molecular information has been gathered on the fathead minnow over the years, the la...
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The toxicity of arsenic(III), chromium(VI) and zinc to groundwater copepods.
Hose, G C; Symington, K; Lott, M J; Lategan, M J
2016-09-01
Groundwater ecosystems globally are threatened by anthropogenic contamination, yet there are few ecotoxicological data using obligate groundwater biota on which to base risk assessments. Copepods are found inhabiting aquifers of different geologies around the world and so are a useful taxon for use in ecotoxicological studies of groundwater. The aim of this study was to test the sensitivity of obligate groundwater copepods to metal contaminants (arsenic(III), chromium(VI) and zinc) in groundwater in static 96 h, 14 days and 28 days exposure tests. The copepods were variably sensitive to As, Cr and Zn, with Cr being the most toxic across all taxa. No taxon was consistently most sensitive and there was no apparent relationship between the hardness, pH and organic carbon concentration of the diluent water and the sensitivity of biota. As expected, toxicity increased with exposure period and we encourage the use of longer exposure periods in future toxicity tests with groundwater organisms to reflect the greater exposure periods likely to be associated with groundwater contamination.
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Delistraty, Damon; Yokel, Jerry
2007-01-01
Columbia River sediments were characterized (metals, organics, porewater toxicity) with samples (n=12) from four dams below the Hanford site. Analyses were supplemented with colocated radionuclide data, along with comparable data from the Priest Rapids dam, immediately upriver from Hanford. Although not statistically significant (Bonferroni P>0.05), metals were generally highest at Priest Rapids, relative to downriver dams. Semivolatiles, Aroclors, and organochlorine pesticides were below method reporting limits. Radionuclide differences across locations were minor (Bonferroni P>0.05). Whereas Microtox showed little toxicity, Daphnia IQ tests exhibited measurable toxicity at all locations (EC50 = 22 - 78% porewater). Ecotoxicological benchmarks for metals were exceeded at several locations, most notably at Priest Rapids. Except for K-40, radionuclides were below benchmarks. Overall, chemistry and ecotoxicity results suggested that sediments may pose a risk to benthic biota, likely due to metals (derived largely from upriver mining) or factors associated with a reducing environment (e.g., low oxygen, high ammonia).
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Methodology for the ecotoxicological evaluation of areas polluted by phosphogypsum wastes.
NASA Astrophysics Data System (ADS)
Martínez-Sanchez, M. J.; Garcia-Lorenzo, M. L.; Perez-Sirvent, C.; Martinez-Lopez, S.; Hernandez-Cordoba, M.; Bech, J.
2012-04-01
In Spain, the production of phosphoric acid, and hence of phosphogypsum, is restricted to a fertilizer industrial site. The residues contain some radionuclides of the U-series and other contaminants. In order to estimate the risk posed by these materials, chemical methods need to be complemented with biological methods. Then, the aim of this study was to develop a battery of bioassays for the ecotoxicological screening of areas polluted by phosphogypsum wastes. Particularly, the toxicity of water samples, sediments and their pore-water extracts was evaluated by using three assays: bacteria, plants and ostracods. The applied bioassays were: the bioluminescence inhibition of Vibrio fischeri in superficial water samples using Microtox® bioassay; the root and shoot elongation inhibition and the mortality of Lepidium sativum, Sorghum saccharatum and Sinapis alba using Phytotoxkit® bioassay; and inhibition of Heterocypris incongruens by way of Ostracodtoxkit®. Proposed methodology allows the identification of contamination sources and non contaminated areas, corresponding to decreasing toxicity values.
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Ecotoxicological evaluation of municipal sludge.
Srivastava, Richa; Tewari, Anamika; Chauhan, Lalit K S; Kumar, Dinesh; Gupta, Shrawan K
2005-02-01
Municipal wastes originating from urban and industrial areas have become a major source of soil, ground and surface water pollution. These undesirable agents in our environment significantly interact with our flora and fauna. The aim of this study was to test samples of municipal sludge (MS) for their ecotoxicological potential by using sensitive bioassays involving a plant, Vicia faba, and the earthworm, Eisenia foetida. A 10% leachate of MS was prepared for the experiments, and V. faba seedlings were exposed to three leachate concentrations (2.5%, 5% and 10%) for 5 days. The findings revealed chromosome aberrations during the metaphase as well as the anaphase of cell division, and inhibition of the mitotic index, which reflects that MS originating from domestic and other human activities may be genotoxic to the living organisms of the ecosystem. Abnormalities in chlorophyll content, plant growth, root length, shoot length and root/shoot length ratio in V. faba clearly indicated the toxicity of the sludge. Behavioural and reproduction studies with E. foetida also provided evidence for the toxic nature of the MS.
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OpenSource lab-on-a-chip physiometer for accelerated zebrafish embryo biotests.
Akagi, Jin; Hall, Chris J; Crosier, Kathryn E; Cooper, Jonathan M; Crosier, Philip S; Wlodkowic, Donald
2014-01-02
Zebrafish (Danio rerio) embryo assays have recently come into the spotlight as convenient experimental models in both biomedicine and ecotoxicology. As a small aquatic model organism, zebrafish embryo assays allow for rapid physiological, embryo-, and genotoxic tests of drugs and environmental toxins that can be simply dissolved in water. This protocol describes prototyping and application of an innovative, miniaturized, and polymeric chip-based device capable of immobilizing a large number of living fish embryos for real-time and/or time-lapse microscopic examination. The device provides a physical address designation to each embryo during analysis, continuous perfusion of medium, and post-analysis specimen recovery. Miniaturized embryo array is a new concept of immobilization and real-time drug perfusion of multiple individual and developing zebrafish embryos inside the mesofluidic device. The OpenSource device presented in this protocol is particularly suitable to perform accelerated fish embryo biotests in ecotoxicology and phenotype-based pharmaceutical screening. Copyright © 2014 John Wiley & Sons, Inc.
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Early life stage (ELS) toxicity of sucralose to fathead minnows, Pimephales promelas.
Stoddard, K I; Huggett, D B
2014-10-01
Sucralose, an intense artificial sweetener, has been detected in wastewater and surface waters at concentrations ranging from ng/L to low µg/L. Although over a hundred studies have been conducted to evaluate the safety of sucralose for human consumption, few studies have focused on the chronic ecotoxicological effects of this compound in fish. As a remedy to this data gap, an early-life stage toxicity test was conducted to assess the effects of sucralose on hatching, survival, and growth of fathead minnows (Pimephales promelas). Hatching, survival, and growth were unaffected by 98 mg/L of sucralose. The Lowest-Observed-Effect Concentration (LOEC) and the No-Observed-Effect Concentration (NOEC) for fathead minnows determined by this study are >98 and 98 mg/L, respectively. The results from this study suggest that the concentrations of sucralose detected in the environment are well below those required to cause adverse effects to developing aquatic organisms.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Traunspurger, W.; Haitzer, M.; Hoess, S.
1997-02-01
The authors present a method using the free-living nematode Caenorhabditis elegans to assess toxicity in liquid medium and whole-sediment setups. Test duration is 72 h; endpoints are body length, number of eggs inside worms, percentage of gravid worms, and number of offspring per worm. The effect of CdCl{sub 2} on C. elegans in liquid-phase exposures is described as an example. Results from a field study with cadmium polluted sediments from the River Elbe (Germany) suggest that nematodes may be useful organisms in assessing toxicity of sediments in the whole phase.
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Environmental factors affecting contaminant toxicity in aquatic and terrestrial vertebrates
Rattner, Barnett A.; Heath, Alan G.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John
2003-01-01
Physical and natural factors have long been known to influence the toxicity of environmental contaminants to vertebrates. The majority of data that address this topic have been derived from studies on fish, highly inbred laboratory rodents, and man.' The degree to which these factors modify toxicity has principally been elucidated by controlled laboratory experiments. Until recently, the significance of such effects to free-ranging vertebrates Figure 23.1 was frequently overlooked in ecological risk assessments.' Drawing upon controlled experiments and observational science, we overview environmental factors that influence pollutant toxicity in fish and wildlife, and present some perspective on their ecotoxicological significance.
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Ecotoxicology of phenylphosphonothioates.
Francis, B M; Hansen, L G; Fukuto, T R; Lu, P Y; Metcalf, R L
1980-01-01
The phenylphosphonothioate insecticides EPN and leptophos, and several analogs, were evaluated with respect to their delayed neurotoxic effects in hens and their environmental behavior in a terrestrial-aquatic model ecosystem. Acute toxicity to insects was highly correlated with sigma sigma of the substituted phenyl group (regression coefficient r = -0.91) while acute toxicity to mammals was slightly less well correlated (regression coefficient r = -0.71), and neurotoxicity was poorly correlated with sigma sigma (regression coefficient r = -0.35). Both EPN and leptophos were markedly more persistent and bioaccumulative in the model ecosystem than parathion. Desbromoleptophos, a contaminant and metabolite of leptophos, was seen to be a highly stable and persistent terminal residue of leptophos. PMID:6159210
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Interspecies extrapolation encompasses two related but distinct topic areas that are germane to quantitative extrapolation and hence computational toxicology-dose scaling and parameter scaling. Dose scaling is the process of converting a dose determined in an experimental animal ...
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Temporal Audiovisual Motion Prediction in 2D- vs. 3D-Environments
Dittrich, Sandra; Noesselt, Tömme
2018-01-01
Predicting motion is essential for many everyday life activities, e.g., in road traffic. Previous studies on motion prediction failed to find consistent results, which might be due to the use of very different stimulus material and behavioural tasks. Here, we directly tested the influence of task (detection, extrapolation) and stimulus features (visual vs. audiovisual and three-dimensional vs. non-three-dimensional) on temporal motion prediction in two psychophysical experiments. In both experiments a ball followed a trajectory toward the observer and temporarily disappeared behind an occluder. In audiovisual conditions a moving white noise (congruent or non-congruent to visual motion direction) was presented concurrently. In experiment 1 the ball reappeared on a predictable or a non-predictable trajectory and participants detected when the ball reappeared. In experiment 2 the ball did not reappear after occlusion and participants judged when the ball would reach a specified position at two possible distances from the occluder (extrapolation task). Both experiments were conducted in three-dimensional space (using stereoscopic screen and polarised glasses) and also without stereoscopic presentation. Participants benefitted from visually predictable trajectories and concurrent sounds during detection. Additionally, visual facilitation was more pronounced for non-3D stimulation during detection task. In contrast, for a more complex extrapolation task group mean results indicated that auditory information impaired motion prediction. However, a post hoc cross-validation procedure (split-half) revealed that participants varied in their ability to use sounds during motion extrapolation. Most participants selectively profited from either near or far extrapolation distances but were impaired for the other one. We propose that interindividual differences in extrapolation efficiency might be the mechanism governing this effect. Together, our results indicate that both a realistic experimental environment and subject-specific differences modulate the ability of audiovisual motion prediction and need to be considered in future research. PMID:29618999
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Temporal Audiovisual Motion Prediction in 2D- vs. 3D-Environments.
Dittrich, Sandra; Noesselt, Tömme
2018-01-01
Predicting motion is essential for many everyday life activities, e.g., in road traffic. Previous studies on motion prediction failed to find consistent results, which might be due to the use of very different stimulus material and behavioural tasks. Here, we directly tested the influence of task (detection, extrapolation) and stimulus features (visual vs. audiovisual and three-dimensional vs. non-three-dimensional) on temporal motion prediction in two psychophysical experiments. In both experiments a ball followed a trajectory toward the observer and temporarily disappeared behind an occluder. In audiovisual conditions a moving white noise (congruent or non-congruent to visual motion direction) was presented concurrently. In experiment 1 the ball reappeared on a predictable or a non-predictable trajectory and participants detected when the ball reappeared. In experiment 2 the ball did not reappear after occlusion and participants judged when the ball would reach a specified position at two possible distances from the occluder (extrapolation task). Both experiments were conducted in three-dimensional space (using stereoscopic screen and polarised glasses) and also without stereoscopic presentation. Participants benefitted from visually predictable trajectories and concurrent sounds during detection. Additionally, visual facilitation was more pronounced for non-3D stimulation during detection task. In contrast, for a more complex extrapolation task group mean results indicated that auditory information impaired motion prediction. However, a post hoc cross-validation procedure (split-half) revealed that participants varied in their ability to use sounds during motion extrapolation. Most participants selectively profited from either near or far extrapolation distances but were impaired for the other one. We propose that interindividual differences in extrapolation efficiency might be the mechanism governing this effect. Together, our results indicate that both a realistic experimental environment and subject-specific differences modulate the ability of audiovisual motion prediction and need to be considered in future research.
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Superresolution SAR Imaging Algorithm Based on Mvm and Weighted Norm Extrapolation
NASA Astrophysics Data System (ADS)
Zhang, P.; Chen, Q.; Li, Z.; Tang, Z.; Liu, J.; Zhao, L.
2013-08-01
In this paper, we present an extrapolation approach, which uses minimum weighted norm constraint and minimum variance spectrum estimation, for improving synthetic aperture radar (SAR) resolution. Minimum variance method is a robust high resolution method to estimate spectrum. Based on the theory of SAR imaging, the signal model of SAR imagery is analyzed to be feasible for using data extrapolation methods to improve the resolution of SAR image. The method is used to extrapolate the efficient bandwidth in phase history field and better results are obtained compared with adaptive weighted norm extrapolation (AWNE) method and traditional imaging method using simulated data and actual measured data.
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Emmanuel, E; Perrodin, Y; Keck, G; Blanchard, J-M; Vermande, P
2005-01-14
In hospitals a large variety of substances are in use for medical purposes such as diagnostics and research. After application, diagnostic agents, disinfectants and excreted non-metabolized pharmaceuticals by patients, reach the wastewater. This form of elimination may generate risks for aquatic organisms. The aim of this study was to present: (i) the steps of an ecological risk assessment and management framework related to hospital effluents evacuating into wastewater treatment plant (WWTP) without preliminary treatment; and (ii) the results of its application on wastewater from an infectious and tropical diseases department of a hospital of a large city in southeastern France. The characterization of effects has been made under two assumptions, which were related to: (a) the effects of hospital wastewater on biological treatment process of WWTP, particularly on the community of organisms in charge of the biological decomposition of the organic matter; (b) the effects on aquatic organisms. COD and BOD5 have been measured for studying global organic pollution. Assessment of halogenated organic compounds was made using halogenated organic compounds absorbable on activated carbon (AOX) concentrations. Heavy metals (arsenic, cadmium, chrome, copper, mercury, nickel, lead and zinc) were measured. Low most probable number (MPP) for faecal coliforms has been considered as an indirect detection of antibiotics and disinfectants presence. For toxicity assessment, bioluminescence assay using Vibrio fischeri photobacteria, 72-h EC50 algae growth Pseudokirchneriella subcapitata and 24-h EC50 on Daphnia magna were used. The scenario allows to a semi-quantitative risk characterization. It needs to be improved on some aspects, particularly those linked to: long term toxicity assessment on target organisms (bioaccumulation of pollutants, genotoxicity, etc.); ecotoxicological interactions between pharmaceuticals, disinfectants used both in diagnostics and in cleaning of surfaces, and detergents used in cleaning of surfaces; the interactions into the sewage network, between the hospital effluents and the aquatic ecosystem.
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Making sense of soil ecotoxicology
Beyer, W. Nelson; Linder, Greg L.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John
1995-01-01
The toxicity of pesticides and environmental contaminants to soil organisms has been measured in studies on earthworms,1 soil arthropods,3-6 soil microorganisms,7 and other soil organisms.8 Toxicity data on earthworms produced in the pesticide registration procedure required by the OECD (Organization for economic cooperation and Development) will provide data on many additional chemicals.9 Deciding how to use the data generated is troublesome. In 1965, Edwards10 suggested that the effects of soil insecticides on soils may remain long after the pesticides have disappeared, and that it was clear that pesticides could drastically change the populations of soil organisms; Edwards noted, however, that the effects did not seem to be serious when compared with the benefits to crop production of using pesticides. Since 1965, many studies have been conducted on changes in soil ecosystems caused by environmental contaminants, but we still know little about what the toxicity to particular groups of soil organisms means to the functioning of the soil ecosystem. the problem was illustrated in discussions at the International Conference on Earthworm Ecotoxicology in Sheffield, England, in 1991. there was general agreement that earthworms ahould be taken into account when evaluating pesticides. However, it was unclear what level of reduction in earthworm populations would reduce soil quality or crop yeild. Because populations of earthworms naturally fluctuate greatly even in the absence of pesticides, and because some soils are fertile without any earthworms, it is difficult to equate their population decreases with damage to the soil ecosystem. Broadbent and Tomlin found that the insecticide carbofuran caused fluctuations in the populations of some microarthropods in a cornfield but, in comparing the effects to those of cultivation or adding compost, they concluded that it was unlikely that litter decomposition was significantly affected.3
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Jos, Angeles; Repetto, Guillermo; Ríos, Juan Carlos; del Peso, Ana; Salguero, Manuel; Hazen, María José; Molero, María Luisa; Fernández-Freire, Paloma; Pérez-Martín, Jose Manuel; Labrador, Verónica; Cameán, Ana
2005-01-26
The occurrence and fate of additives in the aquatic environment is an emerging issue in environmental chemistry. This paper describes the ecotoxicological effects of the commonly used additive butylated hydroxyanisole (BHA) using a test battery, comprising of several different organisms and in vitro test systems, representing a proportion of the different trophic levels. The most sensitive system to BHA was the inhibition of bioluminescence in Vibrio fischeri bacteria, which resulted in an acute low observed adverse effect concentration (LOAEC) of 0.28 microM. The next most sensitive system was the immobilization of the cladoceran Daphnia magna followed by: the inhibition of the growth of the unicellular alga Chlorella vulgaris; the endpoints evaluated in Vero (mammalian) cells (total protein content, LDH activity, neutral red uptake and MTT metabolization), mitotic index and root growth inhibition in the terrestrial plant Allium cepa, and finally, the endpoints used on the RTG-2 salmonid fish cell line (neutral red uptake, total protein content, MTS metabolization, lactate dehydrogenase leakage and activity, and glucose-6-phosphate dehydrogenase activity). Morphological alterations in RTG-2 cells were also assessed and these included loss of cells, induction of cellular pleomorphism, hydropic degeneration and induction of apoptosis at high concentrations. The results from this study also indicated that micronuclei were not induced in A.cepa exposed to BHA. The differences in sensitivity for the diverse systems that were used (EC50 ranged from 1.2 to >500 microM) suggest the importance for a test battery approach in the evaluation of the ecological consequences of chemicals. According to the results, the levels of BHA reported in industrial wastewater would elicit adverse effects in the environment. This, coupled with its potential to bioaccumulate, makes BHA a pollutant of concern not only for acute exposures, but also for the long-term.
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Bouguerra, Sirine; Gavina, Ana; Ksibi, Mohamed; Rasteiro, Maria da Graça; Rocha-Santos, Teresa; Pereira, Ruth
2016-07-01
The huge evolution of nanotechnology and the commercialization of nanomaterials (NMs) positively contributed for innovation in several industrial sectors. Facing this rapid development and the emergence of NMs in the market, the release of this nanometric sized materials in the environment and the possible impact on different ecosystem components attracted the attention of researchers in the last few years. In our study we aimed to assess the impact of titanium silicon oxide nanomaterial (nano-TiSiO4) on soil biota to estimate a risk limit for this material. In the present research a battery of standardized ecotoxicological assays aimed at evaluating a wide range of endpoints (avoidance and reproduction of earthworms and collembolans, emergence/growth of four selected terrestrial plants) were carried out, using OECD artificial soil as test substrate spiked with aqueous suspension of different concentrations of nano-TiSiO4. The results showed a maximum avoidance percentage of 40% for earthworms (Esenia andrei) at the highest concentration tested (1000mgkg(-1) soildw of nano-TiSiO4). No significant effect on the reproductive function of both invertebrate species was recorded. Nevertheless, significant phytotoxic data was registered at least for the growth of dicotyledonous plant species (Lactuca sativa and Lycopersicon lycopersicum) with EC20 values ranging between 236 and 414 mg kg(-1) soildw of nano-TiSiO4 for L. sativa dry mass and fresh mass, respectively. Further, the characterization of nano-TiSiO4 in suspensions used to spike the soil, performed by Dynamic Light Scattering, showed the formation of aggregates with important average size diameter, thus demonstrating that the toxic effects observed were likely not size dependent. A deterministic PNEC (predicted no effect concentration) for this NM of 10.02mg kg(-1) soildw of nano-TiSiO4, is suggested, while no more ecotoxicological information exists. Copyright © 2016 Elsevier Inc. All rights reserved.
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Effective-range function methods for charged particle collisions
NASA Astrophysics Data System (ADS)
Gaspard, David; Sparenberg, Jean-Marc
2018-04-01
Different versions of the effective-range function method for charged particle collisions are studied and compared. In addition, a novel derivation of the standard effective-range function is presented from the analysis of Coulomb wave functions in the complex plane of the energy. The recently proposed effective-range function denoted as Δℓ [Ramírez Suárez and Sparenberg, Phys. Rev. C 96, 034601 (2017), 10.1103/PhysRevC.96.034601] and an earlier variant [Hamilton et al., Nucl. Phys. B 60, 443 (1973), 10.1016/0550-3213(73)90193-4] are related to the standard function. The potential interest of Δℓ for the study of low-energy cross sections and weakly bound states is discussed in the framework of the proton-proton S10 collision. The resonant state of the proton-proton collision is successfully computed from the extrapolation of Δℓ instead of the standard function. It is shown that interpolating Δℓ can lead to useful extrapolation to negative energies, provided scattering data are known below one nuclear Rydberg energy (12.5 keV for the proton-proton system). This property is due to the connection between Δℓ and the effective-range function by Hamilton et al. that is discussed in detail. Nevertheless, such extrapolations to negative energies should be used with caution because Δℓ is not analytic at zero energy. The expected analytic properties of the main functions are verified in the complex energy plane by graphical color-based representations.
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Comparison of De Novo Network Reverse Engineering Methods with Applications to Ecotoxicology
The DREAM competitions for network modeling comparisons have made several points clear: 1) incorporating knowledge beyond gene expression data may improve modeling (e.g., data from knock-out organisms), 2) most techniques do not perform better than random, and 3) more complex met...
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The bioaccumulation potential of neutral organic chemicals (e.g., PCBs, DDT, brominated flame retardants) has received a great deal of attention from scientists in the field of environment toxicology and chemistry over the past four decades. Regulations based on our understanding...
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Ecotoxicogenomics to Support Ecological Risk Assessment: A Case Study with Bisphenol A in Fish
Toxicogenomic approaches are being increasingly applied in the field of ecotoxicology. Given the growing availability of ecotoxicogenomic data, the Agency and the broader scientific community are actively engaged in considering how best to use those data to support ecological ris...
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Social Status Modulates Gene Expression and Metabolite Profiles in the Fathead Minnow Males
The fathead minnow (FHM) is a valuable small fish model for genomic research in ecotoxicology. Our recent studies have successfully used genomic and metabolomic analyses to evaluate responses to endocrine disrupting compounds (EDCs) in urine of the FHM, but these results indicate...
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Paving the Way for Predictive Ecotoxicology in the 21st Century
The ability to conduct traditional whole organism toxicity tests for increasingly wide inventories of chemicals of concern is limited by the resource-intensity of the approach in terms of cost, person-hours, and animal use. In a 2007 report, a National Research Council Committee ...
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USSR and Eastern Europe Scientific Abstracts, Chemistry, Number 58
1978-01-20
fertilization. Miron- ovskaya 808 winter wheat variety was planted in 1972-1974, in rotation after sainfoin. Production conditions of planting and cultivation ...METHODOLOGICAL PRINCIPLES OF PESTICIDE ECOTOXICOLOGY Moscow KHIMIYA V SEL’SKOM KHOZYAYSTVE in Russian No 6, 1977 pp 67-73 SOKOLOV, M. S., Candidate
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A Critical Review of Mode of Action (MOA) Assignment Classifications for Ecotoxicology
There are various structure-based classification schemes to categorize chemicals based on mode of action (MOA) which have been applied for both eco and human health toxicology. With increasing calls to assess thousands of chemicals, some of which have little available informatio...
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Gene prediction in the fathead minnow [Pimephales promelas] genome-presentation
The fathead minnow is a well-established ecotoxicological model organism, having been widely used for regulatory ecotoxicity testing and research for over a half century. While a large amount of molecular information has been gathered on the organism over the years, to date, the ...
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Sediment contamination has resulted in the need to develop an appropriate suite of toxicity tests to assess ecotoxicological impacts on estuarine ecosystems. Existing Environmental Protection Agency (EPA) protocols recommend a number of test organisms, including amphipods, polych...
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Computational Chemistry-based Acute Aquatic Toxicity Mode of Action Assignment
The ability to determine the mode of action (MOA) for a diverse group of chemicals is a critical part of ecological risk assessment and chemical regulation. However, existing MOA assignment approaches in ecotoxicology have been limited to a relatively few MOAs, have high uncertai...
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Structural analysis of cylindrical thrust chambers, volume 1
NASA Technical Reports Server (NTRS)
Armstrong, W. H.
1979-01-01
Life predictions of regeneratively cooled rocket thrust chambers are normally derived from classical material fatigue principles. The failures observed in experimental thrust chambers do not appear to be due entirely to material fatigue. The chamber coolant walls in the failed areas exhibit progressive bulging and thinning during cyclic firings until the wall stress finally exceeds the material rupture stress and failure occurs. A preliminary analysis of an oxygen free high conductivity (OFHC) copper cylindrical thrust chamber demonstrated that the inclusion of cumulative cyclic plastic effects enables the observed coolant wall thinout to be predicted. The thinout curve constructed from the referent analysis of 10 firing cycles was extrapolated from the tenth cycle to the 200th cycle. The preliminary OFHC copper chamber 10-cycle analysis was extended so that the extrapolated thinout curve could be established by performing cyclic analysis of deformed configurations at 100 and 200 cycles. Thus the original range of extrapolation was reduced and the thinout curve was adjusted by using calculated thinout rates at 100 and 100 cycles. An analysis of the same underformed chamber model constructed of half-hard Amzirc to study the effect of material properties on the thinout curve is included.
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The Extrapolation of Elementary Sequences
NASA Technical Reports Server (NTRS)
Laird, Philip; Saul, Ronald
1992-01-01
We study sequence extrapolation as a stream-learning problem. Input examples are a stream of data elements of the same type (integers, strings, etc.), and the problem is to construct a hypothesis that both explains the observed sequence of examples and extrapolates the rest of the stream. A primary objective -- and one that distinguishes this work from previous extrapolation algorithms -- is that the same algorithm be able to extrapolate sequences over a variety of different types, including integers, strings, and trees. We define a generous family of constructive data types, and define as our learning bias a stream language called elementary stream descriptions. We then give an algorithm that extrapolates elementary descriptions over constructive datatypes and prove that it learns correctly. For freely-generated types, we prove a polynomial time bound on descriptions of bounded complexity. An especially interesting feature of this work is the ability to provide quantitative measures of confidence in competing hypotheses, using a Bayesian model of prediction.
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Can Pearlite form Outside of the Hultgren Extrapolation of the Ae3 and Acm Phase Boundaries?
NASA Astrophysics Data System (ADS)
Aranda, M. M.; Rementeria, R.; Capdevila, C.; Hackenberg, R. E.
2016-02-01
It is usually assumed that ferrous pearlite can form only when the average austenite carbon concentration C 0 lies between the extrapolated Ae3 ( γ/ α) and Acm ( γ/ θ) phase boundaries (the "Hultgren extrapolation"). This "mutual supersaturation" criterion for cooperative lamellar nucleation and growth is critically examined from a historical perspective and in light of recent experiments on coarse-grained hypoeutectoid steels which show pearlite formation outside the Hultgren extrapolation. This criterion, at least as interpreted in terms of the average austenite composition, is shown to be unnecessarily restrictive. The carbon fluxes evaluated from Brandt's solution are sufficient to allow pearlite growth both inside and outside the Hultgren Extrapolation. As for the feasibility of the nucleation events leading to pearlite, the only criterion is that there are some local regions of austenite inside the Hultgren Extrapolation, even if the average austenite composition is outside.
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Creatine supplementation and glycemic control: a systematic review.
Pinto, Camila Lemos; Botelho, Patrícia Borges; Pimentel, Gustavo Duarte; Campos-Ferraz, Patrícia Lopes; Mota, João Felipe
2016-09-01
The focus of this review is the effects of creatine supplementation with or without exercise on glucose metabolism. A comprehensive examination of the past 16 years of study within the field provided a distillation of key data. Both in animal and human studies, creatine supplementation together with exercise training demonstrated greater beneficial effects on glucose metabolism; creatine supplementation itself demonstrated positive results in only a few of the studies. In the animal studies, the effects of creatine supplementation on glucose metabolism were even more distinct, and caution is needed in extrapolating these data to different species, especially to humans. Regarding human studies, considering the samples characteristics, the findings cannot be extrapolated to patients who have poorer glycemic control, are older, are on a different pharmacological treatment (e.g., exogenous insulin therapy) or are physically inactive. Thus, creatine supplementation is a possible nutritional therapy adjuvant with hypoglycemic effects, particularly when used in conjunction with exercise.
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Han, Jeonghoon; Won, Eun-Ji; Kang, Hye-Min; Lee, Min-Chul; Jeong, Chang-Bum; Kim, Hui-Su; Hwang, Dae-Sik; Lee, Jae-Seong
2017-11-30
Recently, accidental spills of heavy oil have caused adverse effects in marine organisms. Oil pollution can induce damages on development and reproduction, linking with detrimental effects on diverse molecular levels of genes and proteins in plankton and fish. However, most information was mainly focused on marine vertebrates and consequently, limited information was available in marine invertebrates. Furthermore, there is still a lack of knowledge bridging in vivo endpoints with the functional regulation of cytochrome P450 (CYP) genes in response to oil spill pollution in marine invertebrates. In this paper, adverse effects of oil spill pollution in marine invertebrates are summarized with the importance of CYP genes as a potential biomarker, applying for environmental monitoring to detect oil spill using marine copepods. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Mikó, Zsanett; Ujszegi, János; Gál, Zoltán; Imrei, Zoltán; Hettyey, Attila
2015-10-01
The heavy application of pesticides and its potential effects on natural communities has attracted increasing attention to inadvertent impacts of these chemicals. Toxicologists conventionally use laboratory-based tests to assess lethal concentrations of pesticides. However, these tests often do not take into account indirect, interactive and long-term effects, and tend to ignore different rates of disintegration in the laboratory and under natural conditions. Our aim was to investigate the importance of the experimental venue for ecotoxicology tests. We reared tadpoles of the agile frog (Rana dalmatina) in the laboratory and in outdoor mesocosms and exposed them to three initial concentrations of a glyphosate-based herbicide (0, 2 and 6.5 mg a.e./L glyphosate), and to the presence or absence of caged predators (dragonfly larvae). The type of experimental venue had a large effect on the outcome: The herbicide was less lethal to tadpoles reared in outdoor mesocosms than in the laboratory. Further, while the herbicide had a negative effect on development time and on body mass in the laboratory, tadpoles exposed to the herbicide in mesocosms were larger at metamorphosis and developed faster in comparison to those reared in the absence of the herbicide. The effect of the herbicide on morphological traits of tadpoles also differed between the two venues. Finally, in the presence of the herbicide, tadpoles tended to be more active and to stay closer to the bottom of laboratory containers, while tadpole behaviour shifted in the opposite direction in outdoor mesocosms. Our results demonstrate major discrepancies between results of a classic laboratory-based ecotoxicity test and outcomes of an experiment performed in outdoor mesocosms. Consequently, the use of standard laboratory tests may have to be reconsidered and their benefits carefully weighed against the difficulties of performing experiments under more natural conditions. Tests validating experimentally estimated impacts of herbicides under natural conditions and studies identifying key factors determining the applicability of experimental results are urgently needed. Copyright © 2015 Elsevier B.V. All rights reserved.
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Immediate ecotoxicological effects of short-lived oil spills on marine biota
Brussaard, Corina P. D.; Peperzak, Louis; Beggah, Siham; Wick, Lukas Y.; Wuerz, Birgit; Weber, Jan; Samuel Arey, J.; van der Burg, Bart; Jonas, Arjen; Huisman, Johannes; van der Meer, Jan Roelof
2016-01-01
Marine environments are frequently exposed to oil spills as a result of transportation, oil drilling or fuel usage. Whereas large oil spills and their effects have been widely documented, more common and recurrent small spills typically escape attention. To fill this important gap in the assessment of oil-spill effects, we performed two independent supervised full sea releases of 5 m3 of crude oil, complemented by on-board mesocosm studies and sampling of accidentally encountered slicks. Using rapid on-board biological assays, we detect high bioavailability and toxicity of dissolved and dispersed oil within 24 h after the spills, occurring fairly deep (8 m) below the slicks. Selective decline of marine plankton is observed, equally relevant for early stages of larger spills. Our results demonstrate that, contrary to common thinking, even small spills have immediate adverse biological effects and their recurrent nature is likely to affect marine ecosystem functioning. PMID:27041738
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Immediate ecotoxicological effects of short-lived oil spills on marine biota.
Brussaard, Corina P D; Peperzak, Louis; Beggah, Siham; Wick, Lukas Y; Wuerz, Birgit; Weber, Jan; Samuel Arey, J; van der Burg, Bart; Jonas, Arjen; Huisman, Johannes; van der Meer, Jan Roelof
2016-04-04
Marine environments are frequently exposed to oil spills as a result of transportation, oil drilling or fuel usage. Whereas large oil spills and their effects have been widely documented, more common and recurrent small spills typically escape attention. To fill this important gap in the assessment of oil-spill effects, we performed two independent supervised full sea releases of 5 m(3) of crude oil, complemented by on-board mesocosm studies and sampling of accidentally encountered slicks. Using rapid on-board biological assays, we detect high bioavailability and toxicity of dissolved and dispersed oil within 24 h after the spills, occurring fairly deep (8 m) below the slicks. Selective decline of marine plankton is observed, equally relevant for early stages of larger spills. Our results demonstrate that, contrary to common thinking, even small spills have immediate adverse biological effects and their recurrent nature is likely to affect marine ecosystem functioning.
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A high precision extrapolation method in multiphase-field model for simulating dendrite growth
NASA Astrophysics Data System (ADS)
Yang, Cong; Xu, Qingyan; Liu, Baicheng
2018-05-01
The phase-field method coupling with thermodynamic data has become a trend for predicting the microstructure formation in technical alloys. Nevertheless, the frequent access to thermodynamic database and calculation of local equilibrium conditions can be time intensive. The extrapolation methods, which are derived based on Taylor expansion, can provide approximation results with a high computational efficiency, and have been proven successful in applications. This paper presents a high precision second order extrapolation method for calculating the driving force in phase transformation. To obtain the phase compositions, different methods in solving the quasi-equilibrium condition are tested, and the M-slope approach is chosen for its best accuracy. The developed second order extrapolation method along with the M-slope approach and the first order extrapolation method are applied to simulate dendrite growth in a Ni-Al-Cr ternary alloy. The results of the extrapolation methods are compared with the exact solution with respect to the composition profile and dendrite tip position, which demonstrate the high precision and efficiency of the newly developed algorithm. To accelerate the phase-field and extrapolation computation, the graphic processing unit (GPU) based parallel computing scheme is developed. The application to large-scale simulation of multi-dendrite growth in an isothermal cross-section has demonstrated the ability of the developed GPU-accelerated second order extrapolation approach for multiphase-field model.
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Adipose tissue represents an important and understudied component of the endocrine system. Recent evidence suggests that endocrine-disrupting chemicals (EDCs) may be able to alter lipid development (e.g., adipogenesis) and/or the balance of lipid metabolism. The environmentally a...
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Characterization of Ontogenetic Changes in Gene Expression in the Fathead Minnow Pimephales promelas
The fathead minnow Pimephales promelas is often used for ecotoxicological studies in the US and elsewhere. Recently, researchers have begun looking at changes in gene expression in this species after contaminant exposure, mostly as a way to unravel novel mechanisms of act...
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Ecotoxicological information for most contaminants is limited to a small number of taxa, and these are generally restricted to comparatively hardy organisms that are readily extractable from test media and easily identifiable. Advances in DNA sequencing can now provide a comprehe...
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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
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The adverse outcome pathway (AOP) framework is intended to help support greater use of mechanistic toxicology data as a basis for risk assessment and/or regulatory decision-making. While there have been clear advances in the ability to rapidly generate mechanistically-oriented da...
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Sequencing and De novo Draft Assemblies of the Fathead Minnow (Pimphales promelas)Reference Genome
This study was undertaken to develop genome-scale resources for the fathead minnow (Pimphales promelas) an important model organism widely used in both aquatic ecotoxicology research and in regulatory toxicity testing. We report on the first sequencing and two draft assemblies fo...
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Influence Of Trace Metal Distribution On Its Leachability From Coal Fly Ash
The risks associated with the reuse of coal fly ash in natural environmental settings in terms of their mobility and ecotoxicological significance is largely determined by: (1) the physicochemical conditions the fly ash is placed under; (2) the total leachable metal content in fl...