Standardized Aquatic Microcosms

Taub, Frieda B.

doi:10.1021/es00067a601

Cited by 30 publications

(12 citation statements)

References 12 publications

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“…As a matter of fact, such an approach is helpful to improve the first assessment provided by analysis of contamination level, since knowledge of contaminant concentrations alone is not sufficient to predict effects, especially in the case of complex effluents or materials, where antagonistic or synergetic effects between several pollutants, as well as interactions with organic matter or salts, can be expected (Di Toro et al 2001). In addition, microcosm assays are particularly relevant, as they are an attempt to better represent the complex environment (water column and sediment) and allow to measure effects on rather long exposure durations (Taub 1989). When pollutants are introduced into water column of the microcosms, they partition between aqueous and solid phases, and finally reach the sediment, which constitutes a sink.…”

Section: Discussionmentioning

confidence: 99%

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Ecotoxicological assessment of road runoff residues for aquatic surface ecosystems in a scenario of reuse

2010

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Purpose Road runoff residues are often reused in road and civil works building. Although the physicochemical and ecotoxicological characteristics of these materials are known, no extensive ecotoxicological studies have been carried out on the leachates obtained from these residues once they have been spread and exposed to rainfall. This study was aimed at assessing the ecotoxicological risks for lentic aquatic ecosystems receiving the leachates of road runoff residues, either raw or treated, through granulometric sieving. Materials and methods Thirteen raw materials were collected in sites located in various parts of France, a majority of urban retention ponds with high traffic roads. Three of them were granulometrically sieved (fractions, 2-30 mm, 60 μm to 2 mm, and <60 μm). The materials were characterized on a physicochemical level and submitted to a leaching test reflecting the transfer of pollutants from the solid phase to the aqueous phase when the reused materials are exposed to rainfall. The contents in trace metallic elements of leachates were determined. Ecotoxicological single-species tests and microcosm assays were then carried out on the leachates to predict the potential effects of the leachates reaching a close aquatic lentic ecosystem. Results and discussion Twelve samples out of 22 displayed at least one metal content higher than ecotoxic thresholds. For the samples that were submitted to granulometric sieving, the finest fraction (<60 μm) was also the most contaminated. The metal concentrations of leachates, compared with that of sediments, showed that only a low fraction (most often <0.1%) of sediment metals was mobilised by leaching. However, all leachates showed at least one metal concentration > predicted no effect concentration (PNEC). No acute toxicity was found at concentration <20% leachate (v:v). Among the 15 nonfiltered leachates, only two were toxic to some organisms of microcosms; the others were not toxic at the tested concentration of 10%. Conclusions The results obtained on 13 raw materials and 2 valorizable granulometric fractions suggest absence of acute ecotoxicity and absence of chronic ecotoxicity (21-day exposure) at dilution factor >10. The analysis of metallic contents and bioassay results lead concordantly to propose a no observed effect concentration close to 1% (v:v). On an ecotoxicological point of view, the granulometric fractioning does not seem to produce valorizable fractions, which would be systematically innocuous.

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Section: Discussionmentioning

confidence: 99%

“…They can be aquatic, terrestrian, or mixed. The only standardized microcosm is the standardized aquatic microcosm (SAM) of Taub (1989). Most often used aquatic microcosms are static (no water renewal).…”

Section: Microcosm Assaysmentioning

confidence: 99%

Ecotoxicological assessment of road runoff residues for aquatic surface ecosystems in a scenario of reuse

2010

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“…Mainly, they provide experimental conditions closer to natural systems. In this sense, the results acquire greater relevance from an ecological point of view [3,10,11]. Ideally, a method to assess the environmental impact of pesticide use should take into account quantitatively the dispersion of an amount of pesticide and its major metabolites into air, soil and water, the uptake by organisms and the degradation in each environmental compartment [12].…”

Section: Introductionmentioning

confidence: 99%

Model Study of Factors Influencing Steady State Clearance for Lipophilic Toxicants in Aquatic Microcosms

et al. 2001

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We have studied the distribution and bioelimination of the organophosphorus pesticide parathion in a native microcosm consisting of water, sediment, bivalves and aquatic plants. A common apparent clearance constant for biotic and abiotic components was suggested from the analysis of parathion accumulation and degradation.In this work we developed a global model explaining the toxicokinetics of a lipophilic compound and particurlarly the common steady state degradation in an aquatic microcosm, using a set of linear differential equations. We simulated the distribution and degradation of the compound in the microcosm, and fitted single-compartment equation models to data, estimating the apparent sorption and elimination constants. We verified the existence of a common apparent degradation constant for all the compartments. We infer from the mathematical expressions and corroborate from the simulated data that the apparent degradation constant is equal to the sum of the metabolization rates at each biotic compartment multiplied by the compound mass ratios established at steady state between the biotic and the abiotic compartments.Product kinetics simulation showed that steady state might also be achieved in the different compartments, with the same apparent constant as that obtained for toxicant clearance. As a practical result, the total radioactivity in water would serve to calculate the global clearance constant in a simple experimental way if a radiotracer is used. Physical and chemical degradation and chemical loss due to volatilization and CO 2 diffusion were analyzed in the microcosm model. The assessments of the cases where these factors affect the clearance process as well as the implications emerged are discussed.

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“…These studies complement the previously published research [1,2] examining the impacts of Jet‐A and JP‐4 using the standardized aquatic microcosm (SAM). The SAM system has undergone a long period of development by Taub and coworkers [7–14] and is an American Society for Testing and Materials (ASTM) standard method [15]. The use of microcosms in ecological research has been extensively debated [16–18] but remains one of the best tools available for investigating toxicant impacts on communities without contaminating natural systems.…”

Section: Introductionmentioning

confidence: 99%

A test of the community conditioning hypothesis: Persistence of effects in model ecological structures dosed with the jet fuel jp‐8

Landis

Markiewicz

Matthews

et al. 2000

Enviro Toxic and Chemistry

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The foundation of the community conditioning hypothesis, the persistence of effects, was tested in a series of microcosm experiments. Experiments were conducted with the water‐soluble fraction of the turbine fuel JP‐8 using the standard protocols for the standardized aquatic microcosm (SAM). A repeat trial was conducted using the SAM protocol but with a 126‐d test period, twice the standard duration. The results were examined using a variety of conventional univariate, multivariate, and graphical techniques. The principal conclusions were as follows. Effects are persistent in these model ecological systems long after the degradation of the toxicant. Patterns of impacts are detectable at concentrations 15 times lower than an experimentally derived single‐species EC50. The replicate experiments are not replicable in the specific, but the broad pattern of the disruption of algal‐ herbivore dynamics followed by more subtle effects are consistently repeated. The durability of the indirect effects and therefore the information about historical events appears to be a consistent feature of these microcosm systems. The identity of the treatment groups persists. The critical features of the community conditioning hypothesis—persistence of information within ecologicalsystems and the reappearance of patterns and therefore the nonequilibrium dynamics—are again confirmed. The implications of these findings for environmental toxicology, monitoring, and ecological risk assessment are discussed.

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Standardized Aquatic Microcosms

Cited by 30 publications

References 12 publications

Ecotoxicological assessment of road runoff residues for aquatic surface ecosystems in a scenario of reuse

Ecotoxicological assessment of road runoff residues for aquatic surface ecosystems in a scenario of reuse

Model Study of Factors Influencing Steady State Clearance for Lipophilic Toxicants in Aquatic Microcosms

A test of the community conditioning hypothesis: Persistence of effects in model ecological structures dosed with the jet fuel jp‐8

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