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Sediment Toxicity Identification Evaluation
Citation:
BURGESS, R. M. AND K. T. HO. Sediment Toxicity Identification Evaluation. Chapter S, Ferard and Blaise (ed.), Encyclopedia of Aquatic Ecotoxicology. Springer, New York, NY, 8/13/2013:online, (2013).
Impact/Purpose:
This technical definition describes the meaning and applications of sediment Toxicity Identification Evaluations (TIEs).
Description:
Approach combining chemical manipulations and aquatic toxicity testing, generally with whole organisms, to systematically characterize, identify and confirm toxic substances causing toxicity in whole sediments and sediment interstitial waters. The approach is divided into three phases: Phase I Characterization is where the cause(s) of toxicity are categorized into broad classes of toxic substances, Phase II Identification where the specific toxic substance(s) causing toxicity are determined, and Phase III Confirmation in which the findings of Phases I and II are validated using independent methods. Freshwater and marine whole organism toxicity testing methods are used with chemical manipulations that selectively isolate substances, change substance form, or alter substance bioavailability. Comparison of manipulation effects on toxicity to non-manipulated reference samples (i.e., baseline) allows for the characterization and identification of the toxic substance contributing to the observed toxicity. The approach can be used with whole sediments and interstitial waters. In practice, a sediment Toxicity Identification Evaluation (TIE) would determine the toxic substance(s) causing acute toxicity to an amphipod (as a typical test organism) exposed to a marine sediment. For example, nonionic organic contaminants are found to cause toxicity in Phase I (Characterization) and the pesticide DDT is shown to be the specific toxic substance causing toxicity in Phase II (Identification). An estimation of toxic units in Phase III (Confirmation) demonstrates there is sufficient DDT present in the sediment interstitial water to cause observed toxicity validating the TIE findings.
