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Morrissey C, Fritsch C, Fremlin K, Adams W, Borgå K, Brinkmann M, Eulaers I, Gobas F, Moore DRJ, van den Brink N, Wickwire T. Advancing exposure assessment approaches to improve wildlife risk assessment. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2024; 20:674-698. [PMID: 36688277 DOI: 10.1002/ieam.4743] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/04/2023] [Accepted: 01/18/2023] [Indexed: 06/17/2023]
Abstract
The exposure assessment component of a Wildlife Ecological Risk Assessment aims to estimate the magnitude, frequency, and duration of exposure to a chemical or environmental contaminant, along with characteristics of the exposed population. This can be challenging in wildlife as there is often high uncertainty and error caused by broad-based, interspecific extrapolation and assumptions often because of a lack of data. Both the US Environmental Protection Agency (USEPA) and European Food Safety Authority (EFSA) have broadly directed exposure assessments to include estimates of the quantity (dose or concentration), frequency, and duration of exposure to a contaminant of interest while considering "all relevant factors." This ambiguity in the inclusion or exclusion of specific factors (e.g., individual and species-specific biology, diet, or proportion time in treated or contaminated area) can significantly influence the overall risk characterization. In this review, we identify four discrete categories of complexity that should be considered in an exposure assessment-chemical, environmental, organismal, and ecological. These may require more data, but a degree of inclusion at all stages of the risk assessment is critical to moving beyond screening-level methods that have a high degree of uncertainty and suffer from conservatism and a lack of realism. We demonstrate that there are many existing and emerging scientific tools and cross-cutting solutions for tackling exposure complexity. To foster greater application of these methods in wildlife exposure assessments, we present a new framework for risk assessors to construct an "exposure matrix." Using three case studies, we illustrate how the matrix can better inform, integrate, and more transparently communicate the important elements of complexity and realism in exposure assessments for wildlife. Modernizing wildlife exposure assessments is long overdue and will require improved collaboration, data sharing, application of standardized exposure scenarios, better communication of assumptions and uncertainty, and postregulatory tracking. Integr Environ Assess Manag 2024;20:674-698. © 2023 SETAC.
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Affiliation(s)
- Christy Morrissey
- Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Katharine Fremlin
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | | | - Katrine Borgå
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Markus Brinkmann
- School of Environment and Sustainability and Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Igor Eulaers
- FRAM Centre, Norwegian Polar Institute, Tromsø, Norway
| | - Frank Gobas
- School of Resource & Environmental Management, Simon Fraser University, Burnaby, BC, Canada
| | | | - Nico van den Brink
- Division of Toxicology, University of Wageningen, Wageningen, The Netherlands
| | - Ted Wickwire
- Woods Hole Group Inc., Bourne, Massachusetts, USA
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2
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Matyja K. Sublethal effects of binary mixtures of Cu 2+ and Cd 2+ on Daphnia magna: Standard Dynamic Energy Budget (DEB) model analysis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 334:122142. [PMID: 37414122 DOI: 10.1016/j.envpol.2023.122142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 06/30/2023] [Accepted: 07/03/2023] [Indexed: 07/08/2023]
Abstract
Dynamic Energy Budget theory (DEB) describes mass and energy fluxes that occur in living organisms. DEB models were successfully used to assess the influence of stress, including toxic substances, and changes in pH and temperature, on different organisms. In this study, the Standard DEB model was used to evaluate the toxicity of copper and cadmium ions and their binary mixtures on Daphnia magna. Both metal ions have a significant influence on daphnia growth and reproduction. Different physiological modes of action (pMoA) were applied to primary DEB model parameters. Model predictions for chosen modes of interaction of mixture components were evaluated. The goodness of model fit and the model prediction was assessed to indicate the most likely pMoA and interaction mode. Copper and cadmium influence more than one DEB model primary parameter. Different pMoAs can result in similar model fits, and therefore it is difficult to identify pMoA only by evaluation of the goodness of fit of the model to the growth and reproduction data. Some critical discussion and ideas for model development are therefore provided.
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Affiliation(s)
- Konrad Matyja
- Wroclaw University of Science and Technology, Faculty of Chemistry, Department of Micro, Nano, and Bioprocess Engineering, Ul. Norwida 4/6, 50-373, Wrocław, Poland.
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3
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French-McCay DP, Parkerton TF, de Jourdan B. Bridging the lab to field divide: Advancing oil spill biological effects models requires revisiting aquatic toxicity testing. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 256:106389. [PMID: 36702035 DOI: 10.1016/j.aquatox.2022.106389] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/10/2022] [Accepted: 12/12/2022] [Indexed: 06/18/2023]
Abstract
Oil fate and exposure modeling addresses the complexities of oil composition, weathering, partitioning in the environment, and the distributions and behaviors of aquatic biota to estimate exposure histories, i.e., oil component concentrations and environmental conditions experienced over time. Several approaches with increasing levels of complexity (i.e., aquatic toxicity model tiers, corresponding to varying purposes and applications) have been and continue to be developed to predict adverse effects resulting from these exposures. At Tiers 1 and 2, toxicity-based screening thresholds for assumed representative oil component compositions are used to inform spill response and risk evaluations, requiring limited toxicity data, analytical oil characterizations, and computer resources. Concentration-response relationships are employed in Tier 3 to quantify effects of assumed oil component mixture compositions. Oil spill modeling capabilities presently allow predictions of spatial and temporal compositional changes during exposure, which support mixture-based modeling frameworks. Such approaches rely on summed effects of components using toxic units to enable more realistic analyses (Tier 4). This review provides guidance for toxicological studies to inform the development of, provide input to, and validate Tier 4 aquatic toxicity models for assessing oil spill effects on aquatic biota. Evaluation of organisms' exposure histories using a toxic unit model reflects the current state-of the-science and provides an improved approach for quantifying effects of oil constituents on aquatic organisms. Since the mixture compositions in toxicity tests are not representative of field exposures, modelers rely on studies using single compounds to build toxicity models accounting for the additive effects of dynamic mixture exposures that occur after spills. Single compound toxicity data are needed to quantify the influence of exposure duration and modifying environmental factors (e.g., temperature, light) on observed effects for advancing use of this framework. Well-characterized whole oil bioassay data should be used to validate and refine these models.
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Affiliation(s)
- Deborah P French-McCay
- RPS Ocean Science, 55 Village Square Drive, South Kingstown, Rhode Island 02879, United States.
| | - Thomas F Parkerton
- EnviSci Consulting, LLC, 5900 Balcones Dr, Suite 100, Austin, Texas 77433, United States
| | - Benjamin de Jourdan
- Huntsman Marine Science Centre, 1 Lower Campus Rd, St. Andrews, New Brunswick E5B 2L7, Canada
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4
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Jager T, Goussen B, Gergs A. Using the standard DEB animal model for toxicokinetic-toxicodynamic analysis. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2022.110187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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5
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Vlaeminck K, Viaene KPJ, Van Sprang P, De Schamphelaere KAC. Predicting Combined Effects of Chemical Stressors: Population-Level Effects of Organic Chemical Mixtures with a Dynamic Energy Budget Individual-Based Model. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:2240-2258. [PMID: 35723450 DOI: 10.1002/etc.5409] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/11/2022] [Accepted: 06/10/2022] [Indexed: 06/15/2023]
Abstract
Most regulatory ecological risk-assessment frameworks largely disregard discrepancies between the laboratory, where effects of single substances are assessed on individual organisms, and the real environment, where organisms live together in populations and are often exposed to multiple simultaneously occurring substances. We assessed the capability of individual-based models (IBMs) with a foundation in the dynamic energy budget (DEB) theory to predict combined effects of chemical mixtures on populations when they are calibrated on toxicity data of single substances at the individual level only. We calibrated a DEB-IBM for Daphnia magna for four compounds (pyrene, dicofol, α-hexachlorocyclohexane, and endosulfan), covering different physiological modes of action. We then performed a 17-week population experiment with D. magna (designed using the DEB-IBM), in which we tested mixture combinations of these chemicals at relevant concentrations, in a constant exposure phase (7-week exposure and recovery), followed by a pulsed exposure phase (3-day pulse exposure and recovery). The DEB-IBM was validated by comparing blind predictions of mixture toxicity effects with the population data. The DEB-IBM accurately predicted mixture toxicity effects on population abundance in both phases when assuming independent action at the effect mechanism level. The population recovery after the constant exposure was well predicted, but recovery after the pulse was not. The latter could be related to insufficient consideration of stochasticity in experimental design, model implementation, or both. Importantly, the mechanistic DEB-IBM performed better than conventional statistical mixture assessment methods. We conclude that the DEB-IBM, calibrated using only single-substance individual-level toxicity data, produces accurate predictions of population-level mixture effects and can therefore provide meaningful contributions to ecological risk assessment of environmentally realistic mixture exposure scenarios. Environ Toxicol Chem 2022;41:2240-2258. © 2022 SETAC.
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Affiliation(s)
- Karel Vlaeminck
- Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent University (UGent), Campus Coupure, Ghent, Belgium
- Assessing Risks of Chemicals (ARCHE) Consulting, Ghent, Wondelgem, Belgium
| | - Karel P J Viaene
- Assessing Risks of Chemicals (ARCHE) Consulting, Ghent, Wondelgem, Belgium
| | - Patrick Van Sprang
- Assessing Risks of Chemicals (ARCHE) Consulting, Ghent, Wondelgem, Belgium
| | - Karel A C De Schamphelaere
- Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent University (UGent), Campus Coupure, Ghent, Belgium
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Kim DH, Park JC, Lee JS. G protein-coupled receptors (GPCRs) in rotifers and cladocerans: Potential applications in ecotoxicology, ecophysiology, comparative endocrinology, and pharmacology. Comp Biochem Physiol C Toxicol Pharmacol 2022; 256:109297. [PMID: 35183764 DOI: 10.1016/j.cbpc.2022.109297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/01/2022] [Accepted: 02/12/2022] [Indexed: 12/19/2022]
Abstract
The G protein-coupled receptor (GPCR) superfamily plays a fundamental role in both sensory functions and the regulation of homeostasis, and is highly conserved across the eukaryote taxa. Its functional diversity is related to a conserved seven-transmembrane core and invariant set of intracellular signaling mechanisms. The interplay between these properties is key to the evolutionary success of GPCR. As this superfamily originated from a common ancestor, GPCR genes have evolved via lineage-specific duplications through the process of adaptation. Here we summarized information on GPCR gene families in rotifers and cladocerans based on their evolutionary position in aquatic invertebrates and their potential application in ecotoxicology, ecophysiology, comparative endocrinology, and pharmacology. Phylogenetic analyses were conducted to examine the evolutionary significance of GPCR gene families and to provide structural insight on their role in aquatic invertebrates. In particular, most GPCR gene families have undergone sporadic evolutionary processes, but some GPCRs are highly conserved across species despite the dynamics of GPCR evolution. Overall, this review provides a better understanding of GPCR evolution in aquatic invertebrates and expand our knowledge of the potential application of these receptors in various fields.
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Affiliation(s)
- Duck-Hyun Kim
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea
| | - Jun Chul Park
- Département des Sciences, Université Sainte-Anne, Church Point, NS B0W 1M0, Canada
| | - Jae-Seong Lee
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 16419, South Korea.
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7
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Na J, Kim Y, Song J, Shim T, Cho K, Jung J. Evaluation of the combined effect of elevated temperature and cadmium toxicity on Daphnia magna using a simplified DEBtox model. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 291:118250. [PMID: 34597733 DOI: 10.1016/j.envpol.2021.118250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 08/26/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
Thermal discharge and heatwaves under climate change may increase water temperature. In this study, the individual and combined effect of elevated temperature and cadmium (Cd) toxicity on somatic growth and reproduction of Daphnia magna was evaluated using a simplified dynamic energy budget model (DEBtox). The model predicted that the maximum body length (Lm) would be shorter (3.705 mm) at an elevated temperature of 25 °C than at 20 °C (3.974 mm), whereas the maximum reproduction rate (R˙m) would be higher at 25 °C (5.735) than at 20 °C (5.591). The somatic growth and reproduction of D. magna were significantly (p < 0.05) reduced with increasing Cd concentrations, and the reduction was greater at 25 than at 20 °C. Potentiation of Cd toxicity by elevated temperature was correctly simulated by assuming four toxicological modes of action influencing assimilation, somatic maintenance and growth, and reproduction. Overall, the population growth rate of D. magna was expected to decrease linearly with increasing Cd concentrations, and the decrease was expected to be higher at 25 than at 20 °C. These findings suggest a significant ecological risk of toxic metals at elevated temperature, with a mechanistic interpretation of the potentiation effect using a DEBtox modeling approach.
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Affiliation(s)
- Joorim Na
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Yongeun Kim
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Jinyoung Song
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Taeyong Shim
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Kijong Cho
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Jinho Jung
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea.
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8
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Hansul S, Fettweis A, Smolders E, De Schamphelaere K. Interactive Metal Mixture Toxicity to Daphnia magna Populations as an Emergent Property in a Dynamic Energy Budget Individual-Based Model. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2021; 40:3034-3048. [PMID: 34314541 DOI: 10.1002/etc.5176] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/19/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
Environmental risk assessment of metal mixtures is challenging due to the large number of possible mixtures and interactions. Mixture toxicity data cannot realistically be generated for all relevant scenarios. Therefore, methods for prediction of mixture toxicity from single-metal toxicity data are needed. We tested how well toxicity of Cu-Ni-Zn mixtures to Daphnia magna populations can be predicted based on the Dynamic Energy Budget theory with an individual-based model (DEB-IBM), assuming non-interactivity of metals on the physiological level. We exposed D. magna populations to Cu, Ni, and Zn and their mixture at a fixed concentration ratio. We calibrated the DEB-IBM with single-metal data and generated blind predictions of mixture toxicity (population size over time), with account for uncertainty. We compared the predictive performance of the DEB-IBM with respect to mixture effects on population density and population growth rates with that of two reference models applied on the population level, independent action and concentration addition. Our inferred physiological modes of action (pMoA) differed from literature-reported pMoAs, raising the question of whether this is a result of different model selection approaches, intraspecific variability, or whether different pMoAs might actually drive toxicity in a population context. Observed mixture effects were concentration- and endpoint-dependent. The independent action was overall more accurate than the concentration addition but concentration addition-predicted effects on population growth rate were slightly better. The DEB-IBM most accurately predicted effects on 6-week density, including antagonistic effects at high concentrations, which emerged from non-interactivity at the physiological level. Mixture effects on initial population growth rate appear to be more difficult to predict. To explain why model accuracy is endpoint-dependent, relationships between individual-level and population-level endpoints should be illuminated. Environ Toxicol Chem 2021;40:3034-3048. © 2021 SETAC.
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Affiliation(s)
- Simon Hansul
- Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent, Ghent University, Belgium
| | - Andreas Fettweis
- Department of Earth and Environmental Sciences, Division of Soil and Water Management, KU Leuven, Heverlee, Belgium
| | - Erik Smolders
- Department of Earth and Environmental Sciences, Division of Soil and Water Management, KU Leuven, Heverlee, Belgium
| | - Karel De Schamphelaere
- Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent, Ghent University, Belgium
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9
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Oliveira KMGD, Carvalho EHDS, Santos Filho RD, Sivek TW, Thá EL, Souza IRD, Coelho LDDS, Pimenta MEB, Oliveira GARD, Oliveira DPD, Cestari MM, Leme DM. Single and mixture toxicity evaluation of three phenolic compounds to the terrestrial ecosystem. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 296:113226. [PMID: 34252852 DOI: 10.1016/j.jenvman.2021.113226] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 06/26/2021] [Accepted: 07/03/2021] [Indexed: 06/13/2023]
Abstract
Endocrine-disrupting chemicals (EDCs) are primarily studied regarding endocrine-mediated effects in mammals and fish. However, EDCs can cause toxicity by mechanisms outside the endocrine system, and, as they are released continuously into soils, they may pose risks to terrestrial organisms. In this work, the plant Allium cepa and the earthworm Eisenia foetida were used as test systems to evaluate the toxicity and cyto-/geno-toxicity of three environmental phenols known as EDCs (Bisphenol A - BPA, Octylphenol - OP, Nonylphenol - NP). The tested phenols were evaluated in environmentally relevant concentrations (μg/L) and in single forms and mixture. BPA, OP, and NP did not inhibit the seed germination and root development in A. cepa in their single forms and mixture. However, all single forms of the tested phenols caused cellular and DNA damages in A. cepa, and although these effects persist in the mixtures, the effects were verified at lower levels. These phenols caused acute toxicity to E. foetida after 48 h of exposure and at both conditions evaluated (single forms and mixture); however, unlike A. cepa, in earthworms, mixtures and single forms presented the same level of effects, indicating that interspecies physiological different might influence the mixture toxicity. In summary, our results suggest that BPA, OP, and NP are toxicants to earthworm and cyto-/geno-toxicants to monocotyledonous plants at low concentrations. However, interaction among these phenols reduces the magnitude of their individual effects (antagonistic effect) in the plant test system. Therefore, this study draws attention to the need to raise knowledge about the ecotoxicity of phenolic compounds to help predict their ecological risks and protect non-target terrestrial species.
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Affiliation(s)
- Ketelen Michele Guilherme de Oliveira
- Graduate Program in Genetics, Departament of Genetics, Federal University of Paraná (UFPR), Centro Politécnico, Jardim das Américas, 81531-990, Curitiba, PR, Brazil
| | | | - Ronaldo Dos Santos Filho
- Graduate Program in Genetics, Departament of Genetics, Federal University of Paraná (UFPR), Centro Politécnico, Jardim das Américas, 81531-990, Curitiba, PR, Brazil
| | - Tainá Wilke Sivek
- Graduate Program in Genetics, Departament of Genetics, Federal University of Paraná (UFPR), Centro Politécnico, Jardim das Américas, 81531-990, Curitiba, PR, Brazil
| | - Emanoela Lundgren Thá
- Graduate Program in Genetics, Departament of Genetics, Federal University of Paraná (UFPR), Centro Politécnico, Jardim das Américas, 81531-990, Curitiba, PR, Brazil
| | - Irisdoris Rodrigues de Souza
- Graduate Program in Genetics, Departament of Genetics, Federal University of Paraná (UFPR), Centro Politécnico, Jardim das Américas, 81531-990, Curitiba, PR, Brazil
| | - Lauren Dalat de Sousa Coelho
- Faculty of Pharmacy, Federal University of Goiás (UFG), Environmental Toxicology Research Laboratory (EnvTox), Goiânia, GO, Brazil
| | - Maria Eunice Bertelli Pimenta
- Faculty of Pharmacy, Federal University of Goiás (UFG), Environmental Toxicology Research Laboratory (EnvTox), Goiânia, GO, Brazil
| | - Gisele Augusto Rodrigues de Oliveira
- Faculty of Pharmacy, Federal University of Goiás (UFG), Environmental Toxicology Research Laboratory (EnvTox), Goiânia, GO, Brazil; National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactives (INCT-DATREM), Institute of Chemistry, Araraquara, SP, Brazil
| | - Danielle Palma de Oliveira
- Faculty of Pharmaceutical Sciences of Ribeirão Preto (FCFRP), University of São Paulo (USP), Ribeirão Preto, SP, Brazil; National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactives (INCT-DATREM), Institute of Chemistry, Araraquara, SP, Brazil
| | - Marta Margarete Cestari
- Graduate Program in Genetics, Departament of Genetics, Federal University of Paraná (UFPR), Centro Politécnico, Jardim das Américas, 81531-990, Curitiba, PR, Brazil
| | - Daniela Morais Leme
- Graduate Program in Genetics, Departament of Genetics, Federal University of Paraná (UFPR), Centro Politécnico, Jardim das Américas, 81531-990, Curitiba, PR, Brazil; National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactives (INCT-DATREM), Institute of Chemistry, Araraquara, SP, Brazil.
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Sokolova I. Bioenergetics in environmental adaptation and stress tolerance of aquatic ectotherms: linking physiology and ecology in a multi-stressor landscape. J Exp Biol 2021; 224:224/Suppl_1/jeb236802. [PMID: 33627464 DOI: 10.1242/jeb.236802] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Energy metabolism (encompassing energy assimilation, conversion and utilization) plays a central role in all life processes and serves as a link between the organismal physiology, behavior and ecology. Metabolic rates define the physiological and life-history performance of an organism, have direct implications for Darwinian fitness, and affect ecologically relevant traits such as the trophic relationships, productivity and ecosystem engineering functions. Natural environmental variability and anthropogenic changes expose aquatic ectotherms to multiple stressors that can strongly affect their energy metabolism and thereby modify the energy fluxes within an organism and in the ecosystem. This Review focuses on the role of bioenergetic disturbances and metabolic adjustments in responses to multiple stressors (especially the general cellular stress response), provides examples of the effects of multiple stressors on energy intake, assimilation, conversion and expenditure, and discusses the conceptual and quantitative approaches to identify and mechanistically explain the energy trade-offs in multiple stressor scenarios, and link the cellular and organismal bioenergetics with fitness, productivity and/or ecological functions of aquatic ectotherms.
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Affiliation(s)
- Inna Sokolova
- Marine Biology Department, Institute of Biological Sciences, University of Rostock, 18059 Rostock, Germany .,Department of Maritime Systems, Interdisciplinary Faculty, University of Rostock, 18059 Rostock, Germany
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11
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Vlaeminck K, Viaene KPJ, Van Sprang P, De Schamphelaere KAC. Development and Validation of a Mixture Toxicity Implementation in the Dynamic Energy Budget-Individual-Based Model: Effects of Copper and Zinc on Daphnia magna Populations. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2021; 40:513-528. [PMID: 33259144 DOI: 10.1002/etc.4946] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/21/2020] [Accepted: 11/22/2020] [Indexed: 06/12/2023]
Abstract
Mechanistic population models are gaining considerable interest in ecological risk assessment. The dynamic energy budget approach for toxicity (DEBtox) and the general unified threshold model for survival (GUTS) are well-established theoretical frameworks that describe sublethal and lethal effects of a chemical stressor, respectively. However, there have been limited applications of these models for mixtures of chemicals, especially to predict long-term effects on populations. We used DEBtox and GUTS in an individual-based model (IBM) framework to predict both single and combined effects of copper and zinc on Daphnia magna populations. The model was calibrated based on standard chronic toxicity test results with the single substances. A mixture toxicity implementation based on the general independent action model for mixtures was developed and validated with data from a population experiment with copper and zinc mixtures. Population-level effects of exposure to individual metals were accurately predicted by DEB-IBM. The DEB-IBM framework also allowed us to identify the potential mechanisms underlying these observations. Under independent action the DEB-IBM was able to predict the population dynamics observed in populations exposed to the single metals and their mixtures (R2 > 65% in all treatments). Our modeling shows that it is possible to extrapolate from single-substance effects at the individual level to mixture toxicity effects at the population level, without the need for mixture toxicity data at the individual level from standard mixture toxicity tests. The application of such modeling techniques can increase the ecological realism in risk assessment. Environ Toxicol Chem 2021;40:513-527. © 2020 SETAC.
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Affiliation(s)
- Karel Vlaeminck
- Laboratory of Environmental Toxicology and Aquatic Ecology (GhEnToxLab), Ghent University, Ghent, Belgium
- Assessing Risks of Chemicals (ARCHE) Consulting, Ghent (Wondelgem), Belgium
| | - Karel P J Viaene
- Assessing Risks of Chemicals (ARCHE) Consulting, Ghent (Wondelgem), Belgium
| | - Patrick Van Sprang
- Assessing Risks of Chemicals (ARCHE) Consulting, Ghent (Wondelgem), Belgium
| | - Karel A C De Schamphelaere
- Laboratory of Environmental Toxicology and Aquatic Ecology (GhEnToxLab), Ghent University, Ghent, Belgium
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12
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Marshall MM, McCluney KE. Mixtures of co-occurring chemicals in freshwater systems across the continental US. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115793. [PMID: 33069045 DOI: 10.1016/j.envpol.2020.115793] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 09/24/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
Trace chemicals are common in marine and freshwater ecosystems globally. It is recognized that in the environment, individual chemicals are rarely found in isolation. Insufficient work has examined which chemicals co-occur and which methods best identify these mixtures. Using an existing data set, we found evidence that simple correlation analysis is better at identifying mixtures of commonly co-occurring trace chemicals than more commonly used PCA methods. Moreover, simple correlation analysis, unlike PCA, can be used in cases with unbalanced designs and with data points below reportable limits. Application of this approach allowed identification of 10 groups of chemicals commonly found together in freshwaters of the continental US, representing common "chemical syndromes." Better identification of co-occurring chemical combinations could aid in our understanding of biological and ecological effects of aquatic contaminants. This research provides evidence of correlation analyses as a more effective method for identifying commonly co-occurring aquatic contaminants. We also examined the patterns of these mixtures with a dataset consisting of concentrations of 406 trace chemicals from 38 sample locations across the continental US.
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Affiliation(s)
- Melanie M Marshall
- Wright State University - Lake Campus, Celina, OH, 45822, United States; Bowling Green State University, Bowling Green, OH, 43402, United States.
| | - Kevin E McCluney
- Bowling Green State University, Bowling Green, OH, 43402, United States
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13
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Goussen B, Rendal C, Sheffield D, Butler E, Price OR, Ashauer R. Bioenergetics modelling to analyse and predict the joint effects of multiple stressors: Meta-analysis and model corroboration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 749:141509. [PMID: 32827825 DOI: 10.1016/j.scitotenv.2020.141509] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 05/14/2023]
Abstract
Understanding the consequences of the combined effects of multiple stressors-including stress from man-made chemicals-is important for conservation management, the ecological risk assessment of chemicals, and many other ecological applications. Our current ability to predict and analyse the joint effects of multiple stressors is insufficient to make the prospective risk assessment of chemicals more ecologically relevant because we lack a full understanding of how organisms respond to stress factors alone and in combination. Here, we describe a Dynamic Energy Budget (DEB) based bioenergetics model that predicts the potential effects of single or multiple natural and chemical stressors on life history traits. We demonstrate the plausibility of the model using a meta-analysis of 128 existing studies on freshwater invertebrates. We then validate our model by comparing its predictions for a combination of three stressors (i.e. chemical, temperature, and food availability) with new, independent experimental data on life history traits in the daphnid Ceriodaphnia dubia. We found that the model predictions are in agreement with observed growth curves and reproductive traits. To the best of our knowledge, this is the first time that the combined effects of three stress factors on life history traits observed in laboratory studies have been predicted successfully in invertebrates. We suggest that a re-analysis of existing studies on multiple stressors within the modelling framework outlined here will provide a robust null model for identifying stressor interactions, and expect that a better understanding of the underlying mechanisms will arise from these new analyses. Bioenergetics modelling could be applied more broadly to support environmental management decision making.
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Affiliation(s)
- Benoit Goussen
- Environment Department, University of York, Heslington, York YO10 5DD, UK; Safety and Environmental Assurance Centre, Colworth Science Park, Unilever, Sharnbrook, Bedfordshire, UK.
| | - Cecilie Rendal
- Safety and Environmental Assurance Centre, Colworth Science Park, Unilever, Sharnbrook, Bedfordshire, UK
| | - David Sheffield
- Safety and Environmental Assurance Centre, Colworth Science Park, Unilever, Sharnbrook, Bedfordshire, UK
| | - Emma Butler
- Safety and Environmental Assurance Centre, Colworth Science Park, Unilever, Sharnbrook, Bedfordshire, UK
| | - Oliver R Price
- Safety and Environmental Assurance Centre, Colworth Science Park, Unilever, Sharnbrook, Bedfordshire, UK
| | - Roman Ashauer
- Environment Department, University of York, Heslington, York YO10 5DD, UK
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14
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Sadoul B, Geffroy B, Lallement S, Kearney M. Multiple working hypotheses for hyperallometric reproduction in fishes under metabolic theory. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109228] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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15
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Goodchild CG, Simpson AM, Minghetti M, DuRant SE. Bioenergetics-adverse outcome pathway: Linking organismal and suborganismal energetic endpoints to adverse outcomes. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:27-45. [PMID: 30259559 DOI: 10.1002/etc.4280] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/07/2018] [Accepted: 09/20/2018] [Indexed: 05/21/2023]
Abstract
Adverse outcome pathways (AOPs) link toxicity across levels of biological organization, and thereby facilitate the development of suborganismal responses predictive of whole-organism toxicity and provide the mechanistic information necessary for science-based extrapolation to population-level effects. Thus far AOPs have characterized various acute and chronic toxicity pathways; however, the potential for AOPs to explicitly characterize indirect, energy-mediated effects from toxicants has yet to be fully explored. Indeed, although exposure to contaminants can alter an organism's energy budget, energetic endpoints are rarely incorporated into ecological risk assessment because there is not an integrative framework for linking energetic effects to organismal endpoints relevant to risk assessment (e.g., survival, reproduction, growth). In the present analysis, we developed a generalized bioenergetics-AOP in an effort to make better use of energetic endpoints in risk assessment, specifically exposure scenarios that generate an energetic burden to organisms. To evaluate empirical support for a bioenergetics-AOP, we analyzed published data for links between energetic endpoints across levels of biological organization. We found correlations between 1) cellular energy allocation and whole-animal growth, and 2) metabolic rate and scope for growth. Moreover, we reviewed literature linking energy availability to nontraditional toxicological endpoints (e.g., locomotor performance), and found evidence that toxicants impair aerobic performance and activity. We conclude by highlighting current knowledge gaps that should be addressed to develop specific bioenergetics-AOPs. Environ Toxicol Chem 2019;38:27-45. © 2018 SETAC.
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Affiliation(s)
| | - Adam M Simpson
- Oklahoma State University, Stillwater, Oklahoma, USA
- Penn State Erie, The Behrend College, Erie, Pennsylvania, USA
| | | | - Sarah E DuRant
- Oklahoma State University, Stillwater, Oklahoma, USA
- University of Arkansas, Fayetteville, Arkansas, USA
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16
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Zimmer EI, Preuss TG, Norman S, Minten B, Ducrot V. Modelling effects of time-variable exposure to the pyrethroid beta-cyfluthrin on rainbow trout early life stages. ENVIRONMENTAL SCIENCES EUROPE 2018; 30:36. [PMID: 30294515 PMCID: PMC6153864 DOI: 10.1186/s12302-018-0162-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 08/25/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Available literature and regulatory studies show that the severity of effects of beta-cyfluthrin (a synthetic pyrethroid) on fish is influenced by the magnitude and duration of exposure. To investigate how the exposure pattern to beta-cyfluthrin (constant vs peak) may influence the response of the fish, we used a mechanistic effect model to predict the survival and growth of the rainbow trout over its early life stages (i.e. egg, alevin and swim-up fry). We parameterized a toxicokinetic-toxicodynamic (TKTD) module in combination with a dynamic energy budget model enabling us to describe uptake and elimination, as well as to predict the threshold concentration for survival and sublethal effects (feeding behaviour and growth). This effect model was calibrated using data from an early life stage experiment where trout was exposed to a constant concentration of cyfluthrin. The model was validated by comparing model predictions to independent data from a pulsed-exposure study with early life stages of rainbow trout. RESULTS The co-occurrence of effects on behaviour and growth raised the possibility that these were interrelated, i.e. impairment of feeding behaviour may have led to reduced food intake and slower growth. We, therefore, included 'effect on feeding' as mode of action in the TKTD module. At higher concentrations, the constant exposure led to death. The model was able to adequately capture this effect pattern in the calibration. The model was able to adequately predict the response of fish eggs, alevins and swim-up fry, from both the qualitative (response pattern) and quantitative points of view. CONCLUSIONS Since the model was successfully validated, it can be used to predict survival and growth of early life stages under various realistic time-variable exposure profiles (e.g. profiles from FOCUS surface water modelling) of beta-cyfluthrin.
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Affiliation(s)
| | | | - Steve Norman
- RidgewayEco Harwell Innovation Centre, Oxfordshire, OX11 0QG UK
| | - Barbara Minten
- ADAMA Deutschland GmbH, Edmund-Rumpler-Str. 6, 51149 Cologne, Germany
| | - Virginie Ducrot
- Bayer AG CropScience Division, 40789 Monheim Am Rhein, Germany
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17
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Murphy CA, Nisbet RM, Antczak P, Garcia-Reyero N, Gergs A, Lika K, Mathews T, Muller EB, Nacci D, Peace A, Remien CH, Schultz IR, Stevenson LM, Watanabe KH. Incorporating Suborganismal Processes into Dynamic Energy Budget Models for Ecological Risk Assessment. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2018; 14:615-624. [PMID: 29870141 PMCID: PMC6643959 DOI: 10.1002/ieam.4063] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/27/2018] [Accepted: 05/31/2018] [Indexed: 05/19/2023]
Abstract
A working group at the National Institute for Mathematical and Biological Synthesis (NIMBioS) explored the feasibility of integrating 2 complementary approaches relevant to ecological risk assessment. Adverse outcome pathway (AOP) models provide "bottom-up" mechanisms to predict specific toxicological effects that could affect an individual's ability to grow, reproduce, and/or survive from a molecular initiating event. Dynamic energy budget (DEB) models offer a "top-down" approach that reverse engineers stressor effects on growth, reproduction, and/or survival into modular characterizations related to the acquisition and processing of energy resources. Thus, AOP models quantify linkages between measurable molecular, cellular, or organ-level events, but they do not offer an explicit route to integratively characterize stressor effects at higher levels of organization. While DEB models provide the inherent basis to link effects on individuals to those at the population and ecosystem levels, their use of abstract variables obscures mechanistic connections to suborganismal biology. To take advantage of both approaches, we developed a conceptual model to link DEB and AOP models by interpreting AOP key events as measures of damage-inducing processes affecting DEB variables and rates. We report on the type and structure of data that are generated for AOP models that may also be useful for DEB models. We also report on case studies under development that merge information collected for AOPs with DEB models and highlight some of the challenges. Finally, we discuss how the linkage of these 2 approaches can improve ecological risk assessment, with possibilities for progress in predicting population responses to toxicant exposures within realistic environments. Integr Environ Assess Manag 2018;14:615-624. © 2018 SETAC.
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Affiliation(s)
- Cheryl A Murphy
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan, USA
| | - Roger M Nisbet
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, USA
| | - Philipp Antczak
- Institute for Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Natàlia Garcia-Reyero
- Environmental Laboratory, US Army Engineer Research & Development Center, Vicksburg, Mississippi
| | - Andre Gergs
- gaiac-Research Institute for Ecosystem Analysis and Assessment, Aachen, Germany
| | - Konstadia Lika
- Department of Biology, University of Crete, Voutes University Campus, Heraklion, Greece
| | - Teresa Mathews
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Erik B Muller
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, USA
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Diane Nacci
- US Environmental Protection Agency, Office of Research and Development, Narragansett, Rhode Island
| | - Angela Peace
- Department of Mathematics and Statistics, Texas Tech University, Lubbock, Texas, USA
| | | | - Irvin R Schultz
- Marine Sciences Lab, Pacific NW National Laboratory, Sequim, Washington, USA
- Present address: Lynker Technologies, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, USA
| | - Louise M Stevenson
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, USA
| | - Karen H Watanabe
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, Arizona, USA
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18
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Baas J, Augustine S, Marques GM, Dorne JL. Dynamic energy budget models in ecological risk assessment: From principles to applications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 628-629:249-260. [PMID: 29438934 DOI: 10.1016/j.scitotenv.2018.02.058] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 02/05/2018] [Accepted: 02/05/2018] [Indexed: 06/08/2023]
Abstract
In ecological risk assessment of chemicals, hazard identification and hazard characterisation are most often based on ecotoxicological tests and expressed as summary statistics such as No Observed Effect Concentrations or Lethal Concentration values and No Effect Concentrations. Considerable research is currently ongoing to further improve methodologies to take into account toxico kinetic aspects in toxicological assessments, extrapolations of toxic effects observed on individuals to population effects and combined effects of multiple chemicals effects. In this context, the principles of the Dynamic Energy Budget (DEB), namely the conserved allocation of energy to different life-supporting processes in a wide variety of different species, have been applied successfully to the development of a number of DEB models. DEB models allow the incorporation of effects on growth, reproduction and survival within one consistent framework. This review aims to discuss the principles of the DEB theory together with available DEB models, databases available and applications in ecological risk assessment of chemicals for a wide range of species and taxa. Future perspectives are also discussed with particular emphasis on ongoing research efforts to develop DEB models as open source tools to further support the research and regulatory community to integrate quantitative biology in ecotoxicological risk assessment.
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Affiliation(s)
- Jan Baas
- Centre for Ecology and Hydrology, MacLean Building Benson Lane, Wallingford, Oxfordshire, UK.
| | - Starrlight Augustine
- Akvaplan-niva, Fram - High North Research Centre for Climate and the Environment, 9296 Tromsø, Norway
| | | | - Jean-Lou Dorne
- European Food Safety Authority (EFSA), Scientific Committee and emerging Risks Unit, Parma, Italy
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19
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20
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Ashauer R, Jager T. Physiological modes of action across species and toxicants: the key to predictive ecotoxicology. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:48-57. [PMID: 29090718 DOI: 10.1039/c7em00328e] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
As ecotoxicologists we strive for a better understanding of how chemicals affect our environment. Humanity needs tools to identify those combinations of man-made chemicals and organisms most likely to cause problems. In other words: which of the millions of species are at risk from pollution? And which of the tens of thousands of chemicals contribute most to the risk? We identified our poor knowledge on physiological modes of action (how a chemical affects the energy allocation in an organism), and how they vary across species and toxicants, as a major knowledge gap. We also find that the key to predictive ecotoxicology is the systematic, rigorous characterization of physiological modes of action because that will enable more powerful in vitro to in vivo toxicity extrapolation and in silico ecotoxicology. In the near future, we expect a step change in our ability to study physiological modes of action by improved, and partially automated, experimental methods. Once we have populated the matrix of species and toxicants with sufficient physiological mode of action data we can look for patterns, and from those patterns infer general rules, theory and models.
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Affiliation(s)
- Roman Ashauer
- Environment Department, University of York, Heslington, York YO10 5NG, UK.
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21
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Desforges JP, Levin M, Jasperse L, De Guise S, Eulaers I, Letcher RJ, Acquarone M, Nordøy E, Folkow LP, Hammer Jensen T, Grøndahl C, Bertelsen MF, St Leger J, Almunia J, Sonne C, Dietz R. Effects of Polar Bear and Killer Whale Derived Contaminant Cocktails on Marine Mammal Immunity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:11431-11439. [PMID: 28876915 DOI: 10.1021/acs.est.7b03532] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Most controlled toxicity studies use single chemical exposures that do not represent the real world situation of complex mixtures of known and unknown natural and anthropogenic substances. In the present study, complex contaminant cocktails derived from the blubber of polar bears (PB; Ursus maritimus) and killer whales (KW; Orcinus orca) were used for in vitro concentration-response experiments with PB, cetacean and seal spp. immune cells to evaluate the effect of realistic contaminant mixtures on various immune functions. Cytotoxic effects of the PB cocktail occurred at lower concentrations than the KW cocktail (1 vs 16 μg/mL), likely due to differences in contaminant profiles in the mixtures derived from the adipose of each species. Similarly, significant reduction of lymphocyte proliferation occurred at much lower exposures in the PB cocktail (EC50: 0.94 vs 6.06 μg/mL; P < 0.01), whereas the KW cocktail caused a much faster decline in proliferation (slope: 2.9 vs 1.7; P = 0.04). Only the KW cocktail modulated natural killer (NK) cell activity and neutrophil and monocyte phagocytosis in a concentration- and species-dependent manner. No clear sensitivity differences emerged when comparing cetaceans, seals and PB. Our results showing lower effect levels for complex mixtures relative to single compounds suggest that previous risk assessments underestimate the effects of real world contaminant exposure on immunity. Our results using blubber-derived contaminant cocktails add realism to in vitro exposure experiments and confirm the immunotoxic risk marine mammals face from exposure to complex mixtures of environmental contaminants.
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Affiliation(s)
- Jean-Pierre Desforges
- Department of Bioscience, Arctic Research Centre, Aarhus University , Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Milton Levin
- Department of Pathobiology and Veterinary Science, University of Connecticut , 61 North Eagleville Road, Storrs, Connecticut 06269-3089, United States of America
| | - Lindsay Jasperse
- Department of Pathobiology and Veterinary Science, University of Connecticut , 61 North Eagleville Road, Storrs, Connecticut 06269-3089, United States of America
| | - Sylvain De Guise
- Department of Pathobiology and Veterinary Science, University of Connecticut , 61 North Eagleville Road, Storrs, Connecticut 06269-3089, United States of America
| | - Igor Eulaers
- Department of Bioscience, Arctic Research Centre, Aarhus University , Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Robert J Letcher
- Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University , Ottawa, Ontario Canada K1A 0H3
| | - Mario Acquarone
- Department of Arctic and Marine Biology, University of Tromsø - the Arctic University of Norway , Breivika, 9037 Tromsø, Norway
| | - Erling Nordøy
- Department of Arctic and Marine Biology, University of Tromsø - the Arctic University of Norway , Breivika, 9037 Tromsø, Norway
| | - Lars P Folkow
- Department of Arctic and Marine Biology, University of Tromsø - the Arctic University of Norway , Breivika, 9037 Tromsø, Norway
| | | | - Carsten Grøndahl
- Copenhagen ZOO, Roskildevej 38, PO Box 7, DK-2000 Frederiksberg, Denmark
| | - Mads F Bertelsen
- Copenhagen ZOO, Roskildevej 38, PO Box 7, DK-2000 Frederiksberg, Denmark
| | - Judy St Leger
- SeaWorld Parks and Entertainment, 500 SeaWorld Drive, San Diego, California 92109, United States of America
| | - Javier Almunia
- Loro Parque Fundación, Avda. Loro Parque, s/n 38400 Puerto de la Cruz, Tenerife Spain
| | - Christian Sonne
- Department of Bioscience, Arctic Research Centre, Aarhus University , Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Rune Dietz
- Department of Bioscience, Arctic Research Centre, Aarhus University , Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
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22
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Vu HT, Keough MJ, Long SM, Pettigrove VJ. Toxicological effects of fungicide mixtures on the amphipod Austrochiltonia subtenuis. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:2651-2659. [PMID: 28370236 DOI: 10.1002/etc.3809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 02/23/2017] [Accepted: 03/24/2017] [Indexed: 06/07/2023]
Abstract
Approaches to assess the toxicity of mixtures often use predictive models with acute mortality as an endpoint at relatively high concentrations. However, these approaches do not reflect realistic situations where organisms could be exposed to chemical mixtures over long periods at low concentrations at which no significant mortalities occur. The present study investigated chronic effects of 2 common fungicides, Filan® (active ingredient [a.i]) boscalid) and Systhane™ (a.i. myclobutanil), on the amphipod Austrochiltonia subtenuis at environmentally relevant concentrations under laboratory conditions. Sexually mature amphipods were exposed singly and in combination to Filan (1, 10, and 40 μg a.i./L) and Systhane (3 μg a.i./L) over 28 d. Survival, growth, a wide range of reproduction endpoints, and glutathione-S-transferase (GST) activity were measured at the end of the experiment. Both fungicides had significant independent effects on male growth, sex ratio, and juvenile size. Filan mainly affected female growth and the number of embryos per gravid female, whereas Systhane mainly affected the time for females to become gravid. The combined effects of these fungicides on numbers of gravid females and juveniles were antagonistic, causing a 61% reduction in the number of gravid females and a 77% reduction in the number of juveniles produced at the highest concentrations (40 μg a.i./L of boscalid and 3 μg a.i./L of myclobutanil) compared with the controls. There were no significant effects on survival or GST activity. The present study demonstrated that the effects of mixtures were endpoint dependent and that using a variety of endpoints should be considered for a comprehensive understanding of mixture effects. Also, chronic studies are more informative than acute studies for environmentally relevant fungicide concentrations. Environ Toxicol Chem 2017;36:2651-2659. © 2017 SETAC.
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Affiliation(s)
- Hung T Vu
- Centre for Aquatic Pollution Identification and Management, School of BioSciences, The University of Melbourne, Victoria, Australia
| | - Michael J Keough
- Centre for Aquatic Pollution Identification and Management, School of BioSciences, The University of Melbourne, Victoria, Australia
| | - Sara M Long
- Centre for Aquatic Pollution Identification and Management, School of BioSciences, The University of Melbourne, Victoria, Australia
| | - Vincent J Pettigrove
- Centre for Aquatic Pollution Identification and Management, School of BioSciences, The University of Melbourne, Victoria, Australia
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23
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Brown KE, King CK, Harrison PL. Lethal and behavioral impacts of diesel and fuel oil on the Antarctic amphipod Paramoera walkeri. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:2444-2455. [PMID: 28256740 DOI: 10.1002/etc.3778] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 11/29/2016] [Accepted: 02/28/2017] [Indexed: 06/06/2023]
Abstract
Toxicity testing with Antarctic species is required for risk assessment of fuel spills in Antarctic coastal waters. The lethal and sublethal (movement behavior) sensitivities of adults and juveniles of the Antarctic amphipod Paramoera walkeri to the water accommodated fractions (WAFs) of 3 fuels were estimated in extended-duration tests at -1 °C to 21 d. Response of P. walkeri for lethal hydrocarbon concentrations was slow, with 50% lethal concentrations (LC50s) first able to be estimated at 7 d for adults exposed to Special Antarctic Blend diesel (SAB), which had the highest hydrocarbon concentrations of the 3 fuel WAFs. Juveniles showed greater response to marine gas oil (MGO) and intermediate residual fuel oil (IFO 180) at longer exposure durations and were most sensitive at 21 d to IFO 180 (LC50 = 12 μg/L). Adults were initially more sensitive than juveniles; at 21 d, however, juveniles were more than twice as sensitive as adults to SAB (LC50 = 153 μg/L and 377 μg/L, respectively). Significant effects on movement behavior were evident at earlier time points and lower concentrations than was mortality in all 3 fuel WAFs, and juveniles were highly sensitive to sublethal effects of MGO. These first estimates of Antarctic amphipod sensitivity to diesel and fuel oils in seawater contribute to the development of ecologically relevant risk assessments for management of hydrocarbon contamination in the region. Environ Toxicol Chem 2017;36:2444-2455. © 2017 SETAC.
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Affiliation(s)
- Kathryn E Brown
- Marine Ecology Research Centre, Southern Cross University, Lismore, New South Wales, Australia
- Antarctic Conservation and Management, Australian Antarctic Division, Kingston, Tasmania, Australia
| | - Catherine K King
- Antarctic Conservation and Management, Australian Antarctic Division, Kingston, Tasmania, Australia
| | - Peter L Harrison
- Marine Ecology Research Centre, Southern Cross University, Lismore, New South Wales, Australia
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24
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Robinson A, Hesketh H, Lahive E, Horton AA, Svendsen C, Rortais A, Dorne JL, Baas J, Heard MS, Spurgeon DJ. Comparing bee species responses to chemical mixtures: Common response patterns? PLoS One 2017. [PMID: 28640811 PMCID: PMC5480836 DOI: 10.1371/journal.pone.0176289] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Pollinators in agricultural landscapes can be exposed to mixtures of pesticides and environmental pollutants. Existing mixture toxicity modelling approaches, such as the models of concentration addition and independent action and the mechanistic DEBtox framework have been previously shown as valuable tools for understanding and ultimately predicting joint toxicity. Here we apply these mixture models to investigate the potential to interpret the effects of semi-chronic binary mixture exposure for three bee species: Apis mellifera, Bombus terrestris and Osmia bicornis within potentiation and mixture toxicity experiments. In the potentiation studies, the effect of the insecticide dimethoate with added propiconazole fungicide and neonicotinoid insecticide clothianidin with added tau-fluvalinate pyrethroid acaricide showed no difference in toxicity compared to the single chemical alone. Clothianidin toxicity showed a small scale, but temporally conserved increase in exposure conducted in the presence of propiconazole, particularly for B. terrestris and O. bicornis, the latter showing a near three-fold increase in clothianidin toxicity in the presence of propiconazole. In the mixture toxicity studies, the dominant response patterns were of additivity, however, binary mixtures of clothianidin and dimethoate in A. mellifera, B. terrestris and male O. bicornis there was evidence of a predominant antagonistic interaction. Given the ubiquitous nature of exposures to multiple chemicals, there is an urgent need to consider mixture effects in pollinator risk assessments. Our analyses suggest that current models, particularly those that utilise time-series data, such as DEBtox, can be used to identify additivity as the dominant response pattern and also those examples of interactions, even when small-scale, that may need to be taken into account during risk assessment.
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Affiliation(s)
- Alex Robinson
- Centre for Ecology and Hydrology, Wallingford, Oxon, United Kingdom
| | - Helen Hesketh
- Centre for Ecology and Hydrology, Wallingford, Oxon, United Kingdom
| | - Elma Lahive
- Centre for Ecology and Hydrology, Wallingford, Oxon, United Kingdom
| | - Alice A. Horton
- Centre for Ecology and Hydrology, Wallingford, Oxon, United Kingdom
| | - Claus Svendsen
- Centre for Ecology and Hydrology, Wallingford, Oxon, United Kingdom
| | | | | | - Jan Baas
- Centre for Ecology and Hydrology, Wallingford, Oxon, United Kingdom
| | - Matthew S. Heard
- Centre for Ecology and Hydrology, Wallingford, Oxon, United Kingdom
| | - David J. Spurgeon
- Centre for Ecology and Hydrology, Wallingford, Oxon, United Kingdom
- * E-mail:
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25
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Desforges JPW, Sonne C, Dietz R. Using energy budgets to combine ecology and toxicology in a mammalian sentinel species. Sci Rep 2017; 7:46267. [PMID: 28387336 PMCID: PMC5384198 DOI: 10.1038/srep46267] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/14/2017] [Indexed: 11/17/2022] Open
Abstract
Process-driven modelling approaches can resolve many of the shortcomings of traditional descriptive and non-mechanistic toxicology. We developed a simple dynamic energy budget (DEB) model for the mink (Mustela vison), a sentinel species in mammalian toxicology, which coupled animal physiology, ecology and toxicology, in order to mechanistically investigate the accumulation and adverse effects of lifelong dietary exposure to persistent environmental toxicants, most notably polychlorinated biphenyls (PCBs). Our novel mammalian DEB model accurately predicted, based on energy allocations to the interconnected metabolic processes of growth, development, maintenance and reproduction, lifelong patterns in mink growth, reproductive performance and dietary accumulation of PCBs as reported in the literature. Our model results were consistent with empirical data from captive and free-ranging studies in mink and other wildlife and suggest that PCB exposure can have significant population-level impacts resulting from targeted effects on fetal toxicity, kit mortality and growth and development. Our approach provides a simple and cross-species framework to explore the mechanistic interactions of physiological processes and ecotoxicology, thus allowing for a deeper understanding and interpretation of stressor-induced adverse effects at all levels of biological organization.
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Affiliation(s)
- Jean-Pierre W Desforges
- Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Christian Sonne
- Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Rune Dietz
- Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
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26
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Ashauer R, O'Connor I, Escher BI. Toxic Mixtures in Time-The Sequence Makes the Poison. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:3084-3092. [PMID: 28177231 DOI: 10.1021/acs.est.6b06163] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
"The dose makes the poison". This principle assumes that once a chemical is cleared out of the organism (toxicokinetic recovery), it no longer has any effect. However, it overlooks the other process of re-establishing homeostasis, toxicodynamic recovery, which can be fast or slow depending on the chemical. Therefore, when organisms are exposed to two toxicants in sequence, the toxicity can differ if their order is reversed. We test this hypothesis with the freshwater crustacean Gammarus pulex and four toxicants that act on different targets (diazinon, propiconazole, 4,6-dinitro-o-cresol, 4-nitrobenzyl chloride). We found clearly different toxicity when the exposure order of two toxicants was reversed, while maintaining the same dose. Slow toxicodynamic recovery caused carry-over toxicity in subsequent exposures, thereby resulting in a sequence effect-but only when toxicodynamic recovery was slow relative to the interval between exposures. This suggests that carry-over toxicity is a useful proxy for organism fitness and that risk assessment methods should be revised as they currently could underestimate risk. We provide the first evidence that carry-over toxicity occurs among chemicals acting on different targets and when exposure is several days apart. It is therefore not only the dose that makes the poison but also the exposure sequence.
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Affiliation(s)
- Roman Ashauer
- Department of Environmental Toxicology, Eawag - Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf, Switzerland
- Environment Department, University of York , Heslington, York YO10 5DD, United Kingdom
| | - Isabel O'Connor
- Department of Environmental Toxicology, Eawag - Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf, Switzerland
| | - Beate I Escher
- Department of Environmental Toxicology, Eawag - Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf, Switzerland
- Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
- Environmental Toxicology, Center for Applied Geosciences, Eberhard Karls University , Tübingen, Germany
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27
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Panizzi S, Suciu NA, Trevisan M. Combined ecotoxicological risk assessment in the frame of European authorization of pesticides. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 580:136-146. [PMID: 28012656 DOI: 10.1016/j.scitotenv.2016.10.154] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/19/2016] [Accepted: 10/19/2016] [Indexed: 06/06/2023]
Abstract
Organisms are frequently exposed to mixtures of chemical contaminants in the environment, causing a potential "cocktail effect", or combined effect. The joint action of different molecules with similar or different modes of action could result in a potentially unlimited number of additives, synergistic or antagonistic combinations. Since the large number of contaminants makes it impossible to perform ecotoxicity tests for each potential mixture, a robust approach for prospective environmental risk assessment of chemical mixtures is needed. A number of recent publications by the European Commission and the authorities in charge prove the increasing interest that is spreading in the European community towards the topic of the assessment of chemical mixtures. The current EU regulation for Plant Protection Products authorization (Reg. 1107/2009 EC) explicitly requires the evaluation of the potential combined effects of active substances. We reviewed current methods and limitations of mixture assessment of pesticides (7 fungicides and 4 herbicides) through the analysis of the approaches adopted to investigate possible risks for different non-target organisms. The Concentration Addition (CA) approach was the most used approach to predict multiple toxicity to non-target organisms. The guidance for birds and mammals first introduced standard procedures to assess the multiple toxicity based on on CA concept. The recent aquatic EFSA guidance introduced some requirements to evaluate potential mixture toxicity, while the current guidance requirements for terrestrial organisms still lack clear indications on how to conduct the assessment. Moreover, new indications come from the draft guidance for the assessment of terrestrial plants and in-soil organisms. However, the approval and implementation of these new guidelines are still at a developmental stage. Some final considerations are drawn on the future possibilities to improve risk assessment procedures so as to identify harmful effects of pesticides mixtures on non-target organisms.
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Affiliation(s)
- Silvia Panizzi
- Istituto di Chimica Agraria ed Ambientale, Università Cattolica del Sacro Cuore, Piacenza, Italy.
| | - Nicoleta Alina Suciu
- Istituto di Chimica Agraria ed Ambientale, Università Cattolica del Sacro Cuore, Piacenza, Italy
| | - Marco Trevisan
- Istituto di Chimica Agraria ed Ambientale, Università Cattolica del Sacro Cuore, Piacenza, Italy
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28
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De Hoop L, Viaene KPJ, Schipper AM, Huijbregts MAJ, De Laender F, Hendriks AJ. Time-varying effects of aromatic oil constituents on the survival of aquatic species: Deviations between model estimates and observations. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:128-136. [PMID: 27225858 DOI: 10.1002/etc.3508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 07/28/2015] [Accepted: 05/24/2016] [Indexed: 06/05/2023]
Abstract
There is a need to study the time course of toxic chemical effects on organisms because there might be a time lag between the onset of chemical exposure and the corresponding adverse effects. For aquatic organisms, crude oil and oil constituents originating from either natural seeps or human activities can be relevant case studies. In the present study the authors tested a generic toxicokinetic model to quantify the time-varying effects of various oil constituents on the survival of aquatic organisms. The model is based on key parameters applicable to an array of species and compounds with baseline toxicity reflected by a generic, internal toxicity threshold or critical body burden (CBB). They compared model estimates with experimental data on the effects of 8 aromatic oil constituents on the survival of aquatic species including crustaceans and fish. The average model uncertainty, expressed as the root mean square error, was 0.25 (minimum-maximum, 0.04-0.67) on a scale between 0 and 1. The estimated survival was generally lower than the measured survival right after the onset of oil constituent exposure. In contrast, the model underestimated the maximum mortality for crustaceans and fish observed in the laboratory. Thus, the model based on the CBB concept failed to adequately predict the lethal effects of the oil constituents on crustaceans and fish. Possible explanations for the deviations between model estimates and observations may include incorrect assumptions regarding a constant lethal body burden, the absence of biotransformation products, and the steady state of aromatic hydrocarbon concentrations in organisms. Clearly, a more complex model approach than the generic model used in the present study is needed to predict toxicity dynamics of narcotic chemicals. Environ Toxicol Chem 2017;36:128-136. © 2016 SETAC.
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Affiliation(s)
- Lisette De Hoop
- Institute for Water and Wetland Research, Department of Environmental Science, Radboud University, Nijmegen, The Netherlands
| | - Karel P J Viaene
- Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent University (UGent), Ghent, Belgium
| | - Aafke M Schipper
- Institute for Water and Wetland Research, Department of Environmental Science, Radboud University, Nijmegen, The Netherlands
| | - Mark A J Huijbregts
- Institute for Water and Wetland Research, Department of Environmental Science, Radboud University, Nijmegen, The Netherlands
| | - Frederik De Laender
- Research Unit of Environmental and Evolutionary Biology, University of Namur, Namur, Belgium
| | - A Jan Hendriks
- Institute for Water and Wetland Research, Department of Environmental Science, Radboud University, Nijmegen, The Netherlands
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29
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Velki M, Ečimović S. Important Issues in Ecotoxicological Investigations Using Earthworms. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2017; 239:157-184. [PMID: 27161559 DOI: 10.1007/398_2016_4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The importance and beneficial effects of earthworms on soil structure and quality is well-established. In addition, earthworms have proved to be important model organisms for investigation of pollutant effects on soil ecosystems. In ecotoxicological investigations effects of various pollutants on earthworms were assessed. But some important issues regarding the effects of pollutants on earthworms still need to be comprehensively addressed. In this review several issues relevant to soil ecotoxicological investigations using earthworms are emphasized and guidelines that should be adopted in ecotoxicological investigations using earthworms are given. The inclusion of these guidelines in ecotoxicological studies will contribute to the better quantification of impacts of pollutants and will allow more accurate prediction of the real field effects of pollutants to earthworms.
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Affiliation(s)
- Mirna Velki
- Department of Biology, Josip Juraj Strossmayer University of Osijek, Cara Hadrijana 8/A, Osijek, 31000, Croatia.
| | - Sandra Ečimović
- Department of Biology, Josip Juraj Strossmayer University of Osijek, Cara Hadrijana 8/A, Osijek, 31000, Croatia
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30
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Hesketh H, Lahive E, Horton AA, Robinson AG, Svendsen C, Rortais A, Dorne JL, Baas J, Spurgeon DJ, Heard MS. Extending standard testing period in honeybees to predict lifespan impacts of pesticides and heavy metals using dynamic energy budget modelling. Sci Rep 2016; 6:37655. [PMID: 27995934 PMCID: PMC5171639 DOI: 10.1038/srep37655] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/27/2016] [Indexed: 11/09/2022] Open
Abstract
Concern over reported honeybee (Apis mellifera spp.) losses has highlighted chemical exposure as a risk. Current laboratory oral toxicity tests in A. mellifera spp. use short-term, maximum 96 hour, exposures which may not necessarily account for chronic and cumulative toxicity. Here, we use extended 240 hour (10 day) exposures to examine seven agrochemicals and trace environmental pollutant toxicities for adult honeybees. Data were used to parameterise a dynamic energy budget model (DEBtox) to further examine potential survival effects up to 30 day and 90 day summer and winter worker lifespans. Honeybees were most sensitive to insecticides (clothianidin > dimethoate ≫ tau-fluvalinate), then trace metals/metalloids (cadmium, arsenic), followed by the fungicide propiconazole and herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). LC50s calculated from DEBtox parameters indicated a 27 fold change comparing exposure from 48 to 720 hours (summer worker lifespan) for cadmium, as the most time-dependent chemical as driven by slow toxicokinetics. Clothianidin and dimethoate exhibited more rapid toxicokinetics with 48 to 720 hour LC50s changes of <4 fold. As effects from long-term exposure may exceed those measured in short-term tests, future regulatory tests should extend to 96 hours as standard, with extension to 240 hour exposures further improving realism.
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Affiliation(s)
- H Hesketh
- Centre for Ecology &Hydrology, MacLean Building, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK
| | - E Lahive
- Centre for Ecology &Hydrology, MacLean Building, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK
| | - A A Horton
- Centre for Ecology &Hydrology, MacLean Building, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK
| | - A G Robinson
- Centre for Ecology &Hydrology, MacLean Building, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK
| | - C Svendsen
- Centre for Ecology &Hydrology, MacLean Building, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK
| | - A Rortais
- European Food Safety Authority, 1a, Via Carlo Magno, 1A, 43126 Parma PR, Italy
| | - J-L Dorne
- European Food Safety Authority, 1a, Via Carlo Magno, 1A, 43126 Parma PR, Italy
| | - J Baas
- Centre for Ecology &Hydrology, MacLean Building, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK
| | - D J Spurgeon
- Centre for Ecology &Hydrology, MacLean Building, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK
| | - M S Heard
- Centre for Ecology &Hydrology, MacLean Building, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK
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31
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Goussen B, Price OR, Rendal C, Ashauer R. Integrated presentation of ecological risk from multiple stressors. Sci Rep 2016; 6:36004. [PMID: 27782171 PMCID: PMC5080554 DOI: 10.1038/srep36004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 09/26/2016] [Indexed: 01/24/2023] Open
Abstract
Current environmental risk assessments (ERA) do not account explicitly for ecological factors (e.g. species composition, temperature or food availability) and multiple stressors. Assessing mixtures of chemical and ecological stressors is needed as well as accounting for variability in environmental conditions and uncertainty of data and models. Here we propose a novel probabilistic ERA framework to overcome these limitations, which focusses on visualising assessment outcomes by construct-ing and interpreting prevalence plots as a quantitative prediction of risk. Key components include environmental scenarios that integrate exposure and ecology, and ecological modelling of relevant endpoints to assess the effect of a combination of stressors. Our illustrative results demonstrate the importance of regional differences in environmental conditions and the confounding interactions of stressors. Using this framework and prevalence plots provides a risk-based approach that combines risk assessment and risk management in a meaningful way and presents a truly mechanistic alternative to the threshold approach. Even whilst research continues to improve the underlying models and data, regulators and decision makers can already use the framework and prevalence plots. The integration of multiple stressors, environmental conditions and variability makes ERA more relevant and realistic.
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Affiliation(s)
- Benoit Goussen
- Environment Department, University of York, Heslington, York YO10 5DD, UK.,Safety and Environmental Assurance Centre, Colworth Science Park, Unilever, Sharnbrook, Bedfordshire, UK
| | - Oliver R Price
- Safety and Environmental Assurance Centre, Colworth Science Park, Unilever, Sharnbrook, Bedfordshire, UK
| | - Cecilie Rendal
- Safety and Environmental Assurance Centre, Colworth Science Park, Unilever, Sharnbrook, Bedfordshire, UK
| | - Roman Ashauer
- Environment Department, University of York, Heslington, York YO10 5DD, UK
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32
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Rohr JR, Salice CJ, Nisbet RM. The pros and cons of ecological risk assessment based on data from different levels of biological organization. Crit Rev Toxicol 2016; 46:756-84. [PMID: 27340745 PMCID: PMC5141515 DOI: 10.1080/10408444.2016.1190685] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 05/12/2016] [Accepted: 05/13/2016] [Indexed: 01/15/2023]
Abstract
Ecological risk assessment (ERA) is the process used to evaluate the safety of manufactured chemicals to the environment. Here we review the pros and cons of ERA across levels of biological organization, including suborganismal (e.g., biomarkers), individual, population, community, ecosystem and landscapes levels. Our review revealed that level of biological organization is often related negatively with ease at assessing cause-effect relationships, ease of high-throughput screening of large numbers of chemicals (it is especially easier for suborganismal endpoints), and uncertainty of the ERA because low levels of biological organization tend to have a large distance between their measurement (what is quantified) and assessment endpoints (what is to be protected). In contrast, level of biological organization is often related positively with sensitivity to important negative and positive feedbacks and context dependencies within biological systems, and ease at capturing recovery from adverse contaminant effects. Some endpoints did not show obvious trends across levels of biological organization, such as the use of vertebrate animals in chemical testing and ease at screening large numbers of species, and other factors lacked sufficient data across levels of biological organization, such as repeatability, variability, cost per study and cost per species of effects assessment, the latter of which might be a more defensible way to compare costs of ERAs than cost per study. To compensate for weaknesses of ERA at any particular level of biological organization, we also review mathematical modeling approaches commonly used to extrapolate effects across levels of organization. Finally, we provide recommendations for next generation ERA, submitting that if there is an ideal level of biological organization to conduct ERA, it will only emerge if ERA is approached simultaneously from the bottom of biological organization up as well as from the top down, all while employing mathematical modeling approaches where possible to enhance ERA. Because top-down ERA is unconventional, we also offer some suggestions for how it might be implemented efficaciously. We hope this review helps researchers in the field of ERA fill key information gaps and helps risk assessors identify the best levels of biological organization to conduct ERAs with differing goals.
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Affiliation(s)
| | | | - Roger M. Nisbet
- University of California at Santa Barbara, Santa Barbara, CA 93106-9620
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33
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Jusup M, Sousa T, Domingos T, Labinac V, Marn N, Wang Z, Klanjšček T. Physics of metabolic organization. Phys Life Rev 2016; 20:1-39. [PMID: 27720138 DOI: 10.1016/j.plrev.2016.09.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 09/07/2016] [Indexed: 01/26/2023]
Abstract
We review the most comprehensive metabolic theory of life existing to date. A special focus is given to the thermodynamic roots of this theory and to implications that the laws of physics-such as the conservation of mass and energy-have on all life. Both the theoretical foundations and biological applications are covered. Hitherto, the foundations were more accessible to physicists or mathematicians, and the applications to biologists, causing a dichotomy in what always should have been a single body of work. To bridge the gap between the two aspects of the same theory, we (i) adhere to the theoretical formalism, (ii) try to minimize the amount of information that a reader needs to process, but also (iii) invoke examples from biology to motivate the introduction of new concepts and to justify the assumptions made, and (iv) show how the careful formalism of the general theory enables modular, self-consistent extensions that capture important features of the species and the problem in question. Perhaps the most difficult among the introduced concepts, the utilization (or mobilization) energy flow, is given particular attention in the form of an original and considerably simplified derivation. Specific examples illustrate a range of possible applications-from energy budgets of individual organisms, to population dynamics, to ecotoxicology.
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Affiliation(s)
- Marko Jusup
- Center of Mathematics for Social Creativity, Hokkaido University, 5-8 Kita Ward, Sapporo 060-0808, Japan.
| | - Tânia Sousa
- Maretec, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
| | - Tiago Domingos
- Maretec, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
| | - Velimir Labinac
- Department of Physics, University of Rijeka, R. Matejčić 2, 51000 Rijeka, Croatia
| | - Nina Marn
- Department for Marine and Environmental Research, Rudjer Boskovic Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Zhen Wang
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
| | - Tin Klanjšček
- Department for Marine and Environmental Research, Rudjer Boskovic Institute, Bijenička 54, 10000 Zagreb, Croatia
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34
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Spurgeon D, Hesketh H, Lahive E, Svendsen C, Baas J, Robinson A, Horton A, Heard M. Chronic oral lethal and sub‐lethal toxicities of different binary mixtures of pesticides and contaminants in bees (Apis mellifera, Osmia bicornis and Bombus terrestris). ACTA ACUST UNITED AC 2016. [DOI: 10.2903/sp.efsa.2016.en-1076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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35
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Vidal T, Pereira JL, Abrantes N, Soares AMVM, Gonçalves F. Reproductive and developmental toxicity of the herbicide Betanal® Expert and corresponding active ingredients to Daphnia spp. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:13276-13287. [PMID: 27023815 DOI: 10.1007/s11356-016-6492-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 03/16/2016] [Indexed: 06/05/2023]
Abstract
The commercial herbicide formulation Betanal® Expert and its active ingredients (a.i.s) ethofumesate, phenmedipham and desmedipham were focused in this study. Following questions yielding from a previous study, an in-depth analysis of the reproductive toxicity of the pesticide was made. Long-term exposures of Daphnia magna and Daphnia longispina to Betanal® Expert, to each a.i. and to a customised mixture matching the a.i.s ratio within the commercial formulation were carried out, and deleterious effects in the offspring were recorded. This intended to clarify whether (1) the tested compounds induce reproductive injury; (2) there is interspecific variation in daphnids tolerance to the compounds; (3) there is an interaction between chemicals in combined treatments; and (4) the so-called inert ingredients added to the commercial formulation contribute to the toxicity of the herbicide. Generally, developmental impair was observed in both species (egg abortion and release of undeveloped embryos or dead offspring) at concentrations of any of the a.i.s below 1 mg L(-1). Ethofumesate was invariably the least toxic pesticide, and D. magna tended to be of slightly higher sensitivity to the exposures compared to D. longispina. Joint exposures indicated that the a.i.s can interact, inducing more than and less than additive effects for Betanal® Expert and the customised a.i. mixture, respectively. This indicates that inert ingredients co-formulating the commercial pesticide (which are absent from the customised a.i. mixture) actually contribute to its overall toxicity. This study constitutes an add-on to the discussion on the ecotoxicological framework required for authorisation of pesticide trade and usage. The results support the need to consider test species, long-term hazardous potential and toxicity of commercial formulations rather than solely that of active ingredients, as relevant variables in pesticide regulation.
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Affiliation(s)
- Tânia Vidal
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193, Aveiro, Portugal
| | - Joana Luísa Pereira
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193, Aveiro, Portugal.
| | - Nelson Abrantes
- Department of Environment and Planning & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193, Aveiro, Portugal
| | - Amadeu M V M Soares
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193, Aveiro, Portugal
| | - Fernando Gonçalves
- Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193, Aveiro, Portugal
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36
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Margerit A, Gomez E, Gilbin R. Dynamic energy-based modeling of uranium and cadmium joint toxicity to Caenorhabditis elegans. CHEMOSPHERE 2016; 146:405-412. [PMID: 26741545 DOI: 10.1016/j.chemosphere.2015.12.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 12/07/2015] [Accepted: 12/08/2015] [Indexed: 06/05/2023]
Abstract
Toxicokinetic - toxicodynamic energy-based models offer new alternatives to the commonly used approaches for the analysis of mixture toxicity data. Based on the Dynamic Energy Budget theory, DEBtox models enable the description of several endpoints over time simultaneously under the same framework. However, such model still has to be faced with experimental data in a multi-contamination context. In this study, the predictive capacities of a DEBtox model to describe the uranium and cadmium joint toxicity over the entire growth and reproduction period of the soil nematode Caenorhabditis elegans was examined. The two reference additivity approaches, Concentration Addition and Response addition, implemented in the DEBtox model were tested. Assuming no interaction between the two toxicants through Response addition, the DEBtox model allowed a rather accurate fit of the U and Cd joint effects on the growth and reproduction of C. elegans: an interaction between the two metals at the toxicokinetic or toxicodynamic level seems thus unlikely or has only minor consequences. Interestingly, this study underlines that even if the compounds of a mixture share the same DEBtox physiological mode of action (in this case a decrease in assimilation), the Response addition approach may provide a better fit of joint toxicity data than the Concentration addition approach. Moreover, the present work highlighted limitations in the model predictions which are related to the simplifications of the DEBtox framework and its adaptations to the physiology of C. elegans and which lead to an overestimation of the U and Cd joint toxicity in some cases.
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Affiliation(s)
- Adrien Margerit
- Biogeochemistry, Bioavailability and Radionuclide Transfer Laboratory (PRP-ENV/SERIS/L2BT), Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache, Building 183, BP3, 13115 St-Paul-lez-Durance Cedex, France.
| | - Elena Gomez
- UMR Hydrosciences - Université Montpellier 1, DSESP - Faculté de Pharmacie, BP 14491, No 15 Av Charles Flahault, 34093 Montpellier Cedex 05, France
| | - Rodolphe Gilbin
- Biogeochemistry, Bioavailability and Radionuclide Transfer Laboratory (PRP-ENV/SERIS/L2BT), Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache, Building 183, BP3, 13115 St-Paul-lez-Durance Cedex, France.
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37
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Iwasaki Y, Gauthier P. Concentration addition and response addition to analyze mixture toxicity: Is it worth testing? ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2016; 35:526-527. [PMID: 26923855 DOI: 10.1002/etc.3263] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 09/11/2015] [Accepted: 09/23/2015] [Indexed: 06/05/2023]
Affiliation(s)
- Yuichi Iwasaki
- Research Center for Life and Environmental Sciences, Toyo University, Itakura, Oura, Japan
| | - Patrick Gauthier
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
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38
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Cedergreen N, Nørhave NJ, Svendsen C, Spurgeon DJ. Variable Temperature Stress in the Nematode Caenorhabditis elegans (Maupas) and Its Implications for Sensitivity to an Additional Chemical Stressor. PLoS One 2016; 11:e0140277. [PMID: 26784453 PMCID: PMC4718611 DOI: 10.1371/journal.pone.0140277] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 09/22/2015] [Indexed: 11/18/2022] Open
Abstract
A wealth of studies has investigated how chemical sensitivity is affected by temperature, however, almost always under different constant rather than more realistic fluctuating regimes. Here we compared how the nematode Caenorhabditis elegans responds to copper at constant temperatures (8-24°C) and under fluctuation conditions of low (±4°C) and high (±8°C) amplitude (averages of 12, 16, 20°C and 16°C respectively). The DEBkiss model was used to interpret effects on energy budgets. Increasing constant temperature from 12-24°C reduced time to first egg, life-span and population growth rates consistent with temperature driven metabolic rate change. Responses at 8°C did not, however, accord with this pattern (including a deviation from the Temperature Size Rule), identifying a cold stress effect. High amplitude variation and low amplitude variation around a mean temperature of 12°C impacted reproduction and body size compared to nematodes kept at the matching average constant temperatures. Copper exposure affected reproduction, body size and life-span and consequently population growth. Sensitivity to copper (EC50 values), was similar at intermediate temperatures (12, 16, 20°C) and higher at 24°C and especially the innately stressful 8°C condition. Temperature variation did not increase copper sensitivity. Indeed under variable conditions including time at the stressful 8°C condition, sensitivity was reduced. DEBkiss identified increased maintenance costs and increased assimilation as possible mechanisms for cold and higher copper concentration effects. Model analysis of combined variable temperature effects, however, demonstrated no additional joint stressor response. Hence, concerns that exposure to temperature fluctuations may sensitise species to co-stressor effects seem unfounded in this case.
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Affiliation(s)
- Nina Cedergreen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Copenhagen, Denmark
| | - Nils Jakob Nørhave
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Copenhagen, Denmark
| | - Claus Svendsen
- Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom
| | - David J. Spurgeon
- Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom
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Jager T. Predicting environmental risk: A road map for the future. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2016; 79:572-584. [PMID: 27484139 DOI: 10.1080/15287394.2016.1171986] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Frameworks for environmental risk assessment (ERA) focus on comparing results from separate exposure and effect assessments. Exposure assessment generally relies on mechanistic fate models, whereas the effects assessment is anchored in standard test protocols and descriptive statistics. This discrepancy prevents a useful link between these two pillars of ERA, and jeopardizes the realism and efficacy of the entire process. Similar to exposure assessment, effects assessment requires a mechanistic approach to translate the output of fate models into predictions for impacts on populations and food webs. The aim of this study was to discuss (1) the central importance of the individual level, (2) different strategies of dealing with biological complexity, and (3) the role that toxicokinetic-toxicodynamic (TKTD) models, energy budgets, and molecular biology play in a mechanistic revision of the ERA framework. Consequently, an outline for a risk assessment paradigm was developed that incorporates a mechanistic effects assessment in a consistent manner, and a "roadmap for the future." Such a roadmap may play a critical role to eventually arrive at a more scientific and efficient ERA process, and needs to be used to shape our long-term research agendas.
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Redmond KJ, Berry M, Sanni S, Andersen OK. Effect of dispersed crude oil on the feeding activity, retention efficiency, and filtration rate of differently sized blue mussels (Mytilus edulis). JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2016; 79:658-674. [PMID: 27484145 DOI: 10.1080/15287394.2016.1171996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The use of physiological response endpoints in environmental monitoring represents an opportunity to provide an integrated picture of health status and ecological fitness of individuals, and may provide an indication of potential longer term effects on aquatic organisms in the environment. The feeding behavior response sensitivity of blue mussels (Mytilus edulis) of differing size to dispersed crude oil (DCO) was investigated in a lab exposure experiment. The ability of mussels to recover following a single exposure was also investigated, as well as the response to consecutive exposures, in order to assess the utility of employing the same individuals in chronic environmental monitoring. Feeding physiology was assessed by measuring retention efficiency and filtration rate of individual mussels in a live-algae feeding assay. In addition, the percentage of mussels actively filtering during testing was calculated. The feeding physiology parameters were sensitive and able to discriminate exposed mussels from controls. Further, data indicated that larger mussels appear more suitable in environmental monitoring, as these animals showed both sensitivity and an ability to adapt and recover from exposure while remaining sensitive to subsequent treatments. Smaller mussels were also sensitive to the measured endpoints, even if these animals suffered higher rates of mortality during the exposure. Finally, when exposed to the high concentration of DCO, mussels displayed a tendency to close the valves and terminate filtration.
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Affiliation(s)
- Kirsten J Redmond
- a Department of Mathematics and Natural Sciences , University of Stavanger , 4036 Stavanger , Norway
- b BiotaTools AS, Prof. Olav Hanssensvei 7A , N-4021 Stavanger , Norway
| | - Mark Berry
- b BiotaTools AS, Prof. Olav Hanssensvei 7A , N-4021 Stavanger , Norway
- c International Research Institute of Stavanger/IRIS Environment , Mekjarvik 12, 4070 Randaberg , Norway
| | - Steinar Sanni
- a Department of Mathematics and Natural Sciences , University of Stavanger , 4036 Stavanger , Norway
- c International Research Institute of Stavanger/IRIS Environment , Mekjarvik 12, 4070 Randaberg , Norway
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Redman AD, Parkerton TF. Guidance for improving comparability and relevance of oil toxicity tests. MARINE POLLUTION BULLETIN 2015; 98:156-70. [PMID: 26162510 DOI: 10.1016/j.marpolbul.2015.06.053] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 05/22/2015] [Accepted: 06/28/2015] [Indexed: 05/25/2023]
Abstract
The complex nature and limited aqueous solubility of petroleum substances pose challenges for consistently characterizing exposures in aquatic life hazard assessments. This paper reviews important considerations for the design, conduct and interpretation of laboratory toxicity tests with physically and chemically dispersed oils based on an understanding of the behavior and toxicity of the hydrocarbons that comprise these substances. Guiding principles are provided that emphasize the critical need to understand and, when possible, characterize dissolved hydrocarbon exposures that dictate observed toxicity in these tests. These principles provide a consistent framework for interpreting toxicity studies performed using different substances and test methods by allowing varying dissolved exposures to be expressed in terms of a common metric based on toxic units (TUs). The use of passive sampling methods is also advocated since such analyses provide an analytical surrogate for TUs. The proposed guidance is translated into a series of questions that can be used in evaluating existing data and in guiding design of future studies. Application of these questions to a number of recent publications indicates such considerations are often ignored, thus perpetuating the difficulty of interpreting and comparing results between studies and limiting data use in objective hazard assessment. Greater attention to these principles will increase the comparability and utility of oil toxicity data in decision-making.
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Affiliation(s)
- Aaron D Redman
- ExxonMobil Biomedical Sciences, Inc., 1545 US Highway 22 East, Annandale, NJ 08801, USA.
| | - Thomas F Parkerton
- ExxonMobil Biomedical Sciences, Inc., 22777 Springwood Village Parkway, Spring, TX 77339, USA
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Ashauer R, O'Connor I, Hintermeister A, Escher BI. Death Dilemma and Organism Recovery in Ecotoxicology. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:10136-46. [PMID: 26176278 DOI: 10.1021/acs.est.5b03079] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Why do some individuals survive after exposure to chemicals while others die? Either, the tolerance threshold is distributed among the individuals in a population, and its exceedance leads to certain death, or all individuals share the same threshold above which death occurs stochastically. The previously published General Unified Threshold model of Survival (GUTS) established a mathematical relationship between the two assumptions. According to this model stochastic death would result in systematically faster compensation and damage repair mechanisms than individual tolerance. Thus, we face a circular conclusion dilemma because inference about the death mechanism is inherently linked to the speed of damage recovery. We provide empirical evidence that the stochastic death model consistently infers much faster toxicodynamic recovery than the individual tolerance model. Survival data can be explained by either, slower damage recovery and a wider individual tolerance distribution, or faster damage recovery paired with a narrow tolerance distribution. The toxicodynamic model parameters exhibited meaningful patterns in chemical space, which is why we suggest toxicodynamic model parameters as novel phenotypic anchors for in vitro to in vivo toxicity extrapolation. GUTS appears to be a promising refinement of traditional survival curve analysis and dose response models.
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Affiliation(s)
- Roman Ashauer
- †Department of Environmental Toxicology, Eawag - Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- ‡Environment Department, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Isabel O'Connor
- †Department of Environmental Toxicology, Eawag - Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Anita Hintermeister
- †Department of Environmental Toxicology, Eawag - Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Beate I Escher
- †Department of Environmental Toxicology, Eawag - Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
- §Cell Toxicology, Helmholtz Centre for Environmental Research, UFZ, Leipzig 04318, Germany
- ∥Environmental Toxicology, Center for Applied Geosciences, Eberhard Karls University, Tübingen 72074, Germany
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Spann N, Goedkoop W, Traunspurger W. Phenanthrene bioaccumulation in the nematode Caenorhabditis elegans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:1842-50. [PMID: 25607770 DOI: 10.1021/es504553t] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The contribution of food to the bioaccumulation of xenobiotics and hence toxicity is still an ambiguous issue. It is becoming more and more evident that universal statements cannot be made, but that the relative contribution of food-associated xenobiotics in bioaccumulation depends on species, substance, and environmental conditions. Yet, small-sized benthic or soil animals such as nematodes have largely been disregarded so far. Bioaccumulation of the polycyclic aromatic hydrocarbon phenanthrene in the absence and presence of bacterial food was measured in the nematode Caenorhabditis elegans. Elimination of phenanthrene in the nematodes was biphasic, suggesting that there was a slowly exchanging pool within the nematodes or that biotransformation of phenanthrene took place. Even with food present, dissolved phenanthrene was still the major contributor to bioaccumulated compound in nematode tissues, whereas the diet only contributed about 9%. Toxicokinetic parameters in the treatment without food were different from the ones of the treatment with bacteria, possibly because nematodes depleted their lipid reserves during starvation.
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Affiliation(s)
- Nicole Spann
- Department of Animal Ecology, Bielefeld University , Bielefeld, Germany
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Klok C, Nordtug T, Tamis JE. Estimating the impact of petroleum substances on survival in early life stages of cod (Gadus morhua) using the dynamic energy budget theory. MARINE ENVIRONMENTAL RESEARCH 2014; 101:60-68. [PMID: 25244299 DOI: 10.1016/j.marenvres.2014.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Revised: 09/03/2014] [Accepted: 09/05/2014] [Indexed: 06/03/2023]
Abstract
To estimate the impact of accidental oil-spills on cod fisheries a model framework is developed in which a Dynamic Energy Budget (DEB) model is applied to assess mortality caused by petroleum substances in early life stages. In this paper we report on a literature search and DEB analyses, aiming for cod specific DEB-parameters. Furthermore, we explored the relevance of Fathead minnow DEB-parameters as surrogate by comparing LC50 values calculated from DEB-parameters with literature. Cod specific DEB-parameters could not be estimated based on available literature. LC50 values calculated from Fathead minnow DEB-parameters were higher than literature LC50 for early life stages of fish. Applying an extrapolation factor of 50 to the DEB-parameters resulted in LC50 values that were below literature irrespective of life stage. Therefore, we propose to use the last as an estimate for early life stages in cod and recommend relevant experiments with individual petroleum substances on cod.
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Affiliation(s)
- Chris Klok
- IMARES, Ambachtsweg 8A, P.O. Box 57, 1879AB Den Helder, The Netherlands.
| | - Trond Nordtug
- SINTEF Materials and Chemistry, Environmental Technology, N-7465 Trondheim, Norway
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Delignette-Muller ML, Lopes C, Veber P, Charles S. Statistical handling of reproduction data for exposure-response modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:7544-7551. [PMID: 24892187 DOI: 10.1021/es502009r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Reproduction data collected through standard bioassays are classically analyzed by regression in order to fit exposure-response curves and estimate ECx values (x% effective concentration). But regression is often misused on such data, ignoring statistical issues related to (i) the special nature of reproduction data (count data), (ii) a potential inter-replicate variability, and (iii) a possible concomitant mortality. This paper offers new insights in dealing with those issues. Concerning mortality, particular attention was paid not to waste any valuable data-by dropping all the replicates with mortality-or to bias ECx values. For that purpose we defined a new covariate summing the observation periods during which each individual contributes to the reproduction process. This covariate was then used to quantify reproduction-for each replicate at each concentration-as a number of offspring per individual-day. We formulated three exposure-response models differing by their stochastic part. Those models were fitted to four data sets and compared using a Bayesian framework. The individual-day unit proved to be a suitable approach to use all the available data and prevent bias in the estimation of ECx values. Furthermore, a nonclassical negative-binomial model was shown to correctly describe the inter-replicate variability observed in the studied data sets.
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47
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Jager T, Gudmundsdóttir EM, Cedergreen N. Dynamic modeling of sublethal mixture toxicity in the nematode Caenorhabditis elegans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:7026-7033. [PMID: 24857627 DOI: 10.1021/es501306t] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Dynamic models for toxic effects [toxicokinetic-toxicodynamic (TKTD) models] are increasingly used in the analysis of toxicity data for single-chemical exposure. However, these models also offer a natural extension to the effects of chemical mixtures. Here, we demonstrate how a simple model for the energy budget (DEBkiss) can be used to interpret the effects of cadmium and fluoranthene, in both single and mixed exposure, on the nematode Caenorhabditis elegans. The data for all time points and all end points (growth and reproduction) are combined into a single coherent framework. These modeling results are compared to a more traditional independent-action approach based on the dose-response curves for a single end point at a single time point. The analysis with DEBkiss does not lead to a radically different interpretation of the mixture effects, both indicating an antagonistic interaction in the mixture. The DEBkiss analysis does, however, provide much more insight into the relevant dynamic processes underlying the toxic effect on the organism and allows for the generation of mechanistic hypotheses that can be used to guide further research.
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Affiliation(s)
- Tjalling Jager
- Department of Theoretical Biology, VU University Amsterdam , de Boelelaan 1085, NL-1081 HV Amsterdam, Netherlands
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48
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Jager T, Barsi A, Hamda NT, Martin BT, Zimmer EI, Ducrot V. Dynamic energy budgets in population ecotoxicology: Applications and outlook. Ecol Modell 2014. [DOI: 10.1016/j.ecolmodel.2013.06.024] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Reduced life expectancy model for effects of long term exposure on lethal toxicity with fish. ISRN TOXICOLOGY 2013; 2013:230763. [PMID: 24455314 PMCID: PMC3888739 DOI: 10.1155/2013/230763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 10/29/2013] [Indexed: 11/18/2022]
Abstract
A model based on the concept of reduction in life expectancy (RLE model) as a result of long term exposure to toxicant has been developed which has normal life expectancy (NLT) as a fixed limiting point for a species. The model is based on the equation (LC50 = a ln(LT50) + b) where a and b are constants. It was evaluated by plotting ln LT50 against LC50 with data on organic toxicants obtained from the scientific literature. Linear relationships between LC50 and ln LT50 were obtained and a Calculated NLT was derived from the plots. The Calculated NLT obtained was in good agreement with the Reported NLT obtained from the literature. Estimation of toxicity at any exposure time and concentration is possible using the model. The use of NLT as a reference point is important since it provides a data point independent of the toxicity data set and limits the data to the range where toxicity occurs. This novel approach, which represents a departure from Haber's rule, can be used to estimate long term toxicity from limited available acute toxicity data for fish exposed to organic biocides.
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Novák J, Giesy JP, Klánová J, Hilscherová K. In vitro effects of pollutants from particulate and volatile fractions of air samples-day and night variability. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:6620-6627. [PMID: 23613208 DOI: 10.1007/s11356-013-1726-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 04/08/2013] [Indexed: 06/02/2023]
Abstract
Chemicals in air were characterized for potential interference with signaling of estrogen, androgen, and arylhydrocarbon (AhR) receptors, which are known to play an important role in endocrine-disruptive changes in vivo. Previously, effects of this type have been studied mainly in particulate matter in the ambient air from various localities. In this study, both volatile and particulate fractions of air from three sites in Banja Luka region (Bosnia and Herzegovina) were investigated to describe the distribution of endocrine-disrupting contaminants on a small spatial scale. Circadian variability of air pollution was investigated by collecting samples during both day and night. Air samples collected from urban localities at night were more potent in producing the AhR-mediated effects than those collected during daytime. This trend was not observed at the reference rural location. None of the samples showed significant estrogenic or androgenic activity. On the other hand, anti-androgenicity was detected in both particulate and vapor phases, while anti-estrogenicity was detected only in the particulate fraction of air from all localities. The AhR-mediated potencies of samples were associated primarily with non-persistent compounds. Based on the concentrations of 28 individual compounds, PAHs accounted for approximately 30 % of the AhR-mediated potency determined by the bioassay. The results show that there can be a significant difference between levels of bioactive compounds in air between daytime and nighttime.
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Affiliation(s)
- Jiří Novák
- Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.
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