Body residues: A key variable to analyze toxicity tests with Chironomus riparius exposed to copper-spiked sediments

Laboratoire d'écotoxicologie, Cemagref, 3bis quai Chauveau, C.P. 220, 69336 Lyon Cedex 9, France.
Ecotoxicology and Environmental Safety (Impact Factor: 2.76). 07/2005; 61(2):160-7. DOI: 10.1016/j.ecoenv.2004.11.001
Source: PubMed


Fourth instar Chironomus riparius larvae were exposed to four sediments spiked with copper. Length and copper concentration in the tissue were monitored daily. Kinetics data analysis was performed by fitting a one-compartment model. The analysis of growth data was performed using an energy-based approach which estimates a no-effect concentration (NEC). The elimination rate of copper did not depend on the sediment characteristics, whereas the bioconcentration factor differed by a factor of 10 among the tested sediments, accounting for differences in copper bioavailability. Consequently, the NEC expressed in term of exposure concentrations differed substantially between sediments. In contrast, the NEC expressed in terms of body residues did not depend on the sediment characteristics. This work links, for the first time, a mechanistic effects model with the critical body residue approach, and could contribute to develop relevant tools for sediment risk assessment.

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    • "In the environment sediment metal contaminants are present as mixtures (Stewart, 1999), therefore, cause and effects of individual metals on benthic biota may be additive or antagonistic (Campana et al., 2013). In this context, laboratory controlled single metal spiked sediment toxicity assessments are increasingly being used in sediment risk assessments to determine the effects of individual metals (Marchese et al., 2008; Pasteris et al., 2003; Péry et al., 2005). The exposure-dose–response framework is one of the most useful approaches in sediment risk assessment because it integrates the metal concentrations in the exposure medium with organisms' metal accumulation and impairment of biological processes (Giguère et al., 2003; Taylor and Maher, 2010, 2012a, 2013). "
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    ABSTRACT: To evaluate the use of the freshwater bivalve Hyridella australis as a potential biomonitor for zinc contamination in freshwater sediments, the bioavailability and toxicity of zinc contaminated sediments (low 44 ± 5, medium 526 ± 41, high 961 ± 38 μg/g dry mass) were investigated in laboratory microcosms for 28 days by examining H. australis exposure-dose–response relationships. Zinc concentrations in sediments and surface waters were measured as zinc exposure. Zinc in whole organism soft body tissues and five individual tissues were measured as organism zinc dose. Sub-cellular localisation of zinc in hepatopancreas tissues was investigated to further understand the zinc handling strategies and tolerance of H. australis. Total antioxidant capacity, lipid peroxidation and lysosomal membrane stability were measured in hepatopancreas tissues as zinc induced biomarker responses. Accumulated zinc concentrations in whole body tissues of H. australis reflected the zinc exposure and exhibited exposure dependent zinc accumulation at day 28. Gills accumulated significantly higher zinc concentrations than other tissues, however, no significant differences in zinc accumulation between treatments were detected for any of the individual tissues analysed. Analysis of individual tissue zinc concentrations, therefore, may not offer any advantages for monitoring bioavailable zinc in freshwater environments with this organism. Relationships between tissue zinc and calcium concentration suggest accumulation of zinc by H. australis may have occurred as an analogue of calcium which is a major constituent in shell and granules of unionid bivalves. A high percentage of accumulated zinc in the hepatopancreas tissues was detoxified and stored in metallothionein like proteins and metal rich granules. Of the zinc accumulated in the biologically active metal pool, 59–70% was stored in the lysosome + microsome fraction. At the concentrations tested, increasing zinc exposure resulted in decreasing total antioxidant capacity and measurable increases in the sublethal effects, lipid peroxidation and lysosomal membrane destabilisation, were observed. Based on exposure-dose analysis, H. australis partially regulates zinc uptake and weakly exhibits bioavailability of zinc in freshwater environments, however, exposure-response analysis shows zinc induced toxicological effects, suggesting the potential of this organism as a biomonitor for zinc in heavily contaminated freshwater environments.
    Full-text · Article · Sep 2014 · Aquatic Toxicology
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    • "This is not unusual for tests with metal-spiked sediments. For instance, Pery et al. (2005) found differences in NEC values of one order of magnitude for C. riparius exposed to different copper-spiked sediments. To our knowledge, only one other study assessed the effect of uranium-spiked sediment on a benthic invertebrate, Hyalella azteca (Beak International 1998). "
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    ABSTRACT: Natural populations are chronically exposed to various pollutants over many generations. It is thus crucial to understand and quantify adaptive dynamics of stressed populations in order to increase the relevance of ecotoxicological risk assessment. However, long-term consequences to population exposure are not much studied yet. The present study investigated evolutionary responses of Chironomus riparius populations exposed to uranium (heavy metal pollutant) and to assess the underlying mechanisms. To fulfil our objective, we produced data with organisms exposed to four relevant concentrations of uranium through eight successive generations. We built an individual-based (IBM) model of C. riparius population dynamics to analyse these data and to test several assumptions about the mechanisms involved in the phenotypic changes. The IBM was based on a dynamic energy budget (DEB) model for C. riparius by Pery et al. (2002). DEB models account mathematically for the acquisition and use of energy to describe and predict growth, maintenance, development and reproduction of living organisms. The IBM accounted for the influence of the test conditions on the observations over eight generations and highlighted some trait evolution such as time to emergence and adult size in control conditions. The model was then used to analyse the exposed population data. Our results showed that exposure to uranium led to a phenotypic selection via a differential survival characterised by longer time to emergence and smaller larval maximal size. As a general conclusion, IBMs based on DEB-based modelling developed to analyse multi-generation experiments are very promising for understanding and quantifying long term selection and tolerance mechanisms in a population under toxic stress.
    Full-text · Article · Mar 2012 · Ecotoxicology
    • "This is not unusual for tests with metal-spiked sediments. For instance, Pery et al. (2005) found differences in NEC values of one order of magnitude for C. riparius exposed to different copper-spiked sediments. To our knowledge, only one other study assessed the effect of uranium-spiked sediment on a benthic invertebrate, Hyalella azteca (Beak International 1998). "

    No preview · Conference Paper · Apr 2011
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