Development and Application of Sediment Toxicity Tests for Regulatory Purposes

Abstract

Undisturbed sediments tend to accumulate many chemical compounds, and so act as both as sinks of sources of contaminants. Currently, the ecotoxicological assessment of sediments is mainly restricted to chemical analysis and acute toxicity testing using microorganisms. Sediments are not homogenous, but are composed of whole sediment, sediment‐water interface, pore water, and elutriate. Examination of any single sediment phase may be insufficient to give an accurate ecotoxicological assessment. A comprehensive assessment of potential sediment toxicity requires the consideration of multiple exposure phases and multiple test models representing different trophic levels. We recommend that sediment toxicity assessments should be further developed and evaluated to be used in a tiered approach, consisting of screening using short‐term general toxicity tests (Tier 1); hazard identification applying more specific (multiple) endpoints in multiorganism experiments, representing different trophic levels and habitats associated with sediments, as well as different modes of bioavailability by using both sediment extracts and whole sediments (Tier 2); and in situ ecosystem function, e.g., lifetime reproductive success, and components of biodiversity (Tier 3). Here we summarize some of the key sediment toxicity test systems in use and/or under development.

Predicting toxicity in marine sediment in Taranto Gulf (Ionian Sea, Southern Italy) using Sediment Quality Guidelines and a battery bioassay

“…The use of a variety of species representative of different trophic levels, habitats and sensitivity to toxicant allows to evaluate the toxic potential of contaminants considering several exposure routes (unmodified whole sediment, porewater, elutriate) and different endpoints effects on the basis of sensitivity. This approach could increase the probability of identifying sediment correctly that would be expected to be toxic to aquatic organisms (Bombardier and Bermingham 1999;Chapman et al 2002;Davoren et al 2005;Hartl et al 2005). In this study, bioassays, were performed including two species of amphipods Gammarus aequicauda and Corophium insidiosum, one species of isopod Idotea baltica and bivalve Mytilus galloprovincialis larvae.…”

A Two-Species Biomarker Model for the Assessment of Sediment Toxicity in the Marine and Estuarine Environment Using the Comet Assay

“…[9] Although there are several accessible studies demonstrating the merits a of multi-species endpoint approach, most ecotoxicological sediment assessments examine only single species endpoints. Although the recent in vitro analysis Downloaded by [University of Connecticut] at 09:47 13 October 2014 of DNA damage in cell lines, exposed to fractionated sediment extracts, has been demonstrated to be a useful tool for assessing sediment genotoxicity, [12] this approach does not take account of bioavailability or potential synergistic effects of complex contaminant mixtures present in whole sediment.…”

“…There are many potential methods of sediment toxicity assessment, [9] however there is increasing interest in using end points involving DNA integrity. [10][11][12][13][14][15][16] The examination of DNA strand breaks in individual cells, following in vitro or in vivo exposure to pollutants, has become a sensitive biomarker of genotoxicity.…”

Biomarkers in Integrated Ecotoxicological Sediment Assessment

“…Therefore it is imperative that suitable containers are used to collect environmental and biological samples, such as high -density polyethylene or polytetrafl uroethylene environmental variables (Hartl et al 2005 ); these may provide data for contaminant fate and impact assessment models. Therefore it is imperative that suitable containers are used to collect environmental and biological samples, such as high -density polyethylene or polytetrafl uroethylene environmental variables (Hartl et al 2005 ); these may provide data for contaminant fate and impact assessment models.…”

“…A comprehensive assessment of potential sediment toxicity requires a tiered approach considering multiple exposure phases and test models representing different trophic levels, levels of biological organization, and sediment related habitats (Davoren et al 2005 ;Hartl et al 2005 ). This integrated approach should involve the use of short -term general tests using sediment extracts (tier 1); the application of hazard identifi cation models, and more specifi c (multiple) endpoints in multi -organism experiments, representing different trophic levels, habitats associated with sediments, routes of exposure, and bioavailability by using both sediment extracts and whole sediments (tier 2) (Hartl et al 2006 ); and the assessment of in situ ecosystem function through lifetime reproductive success and components of biodiversity (tier 3) (Nendza 2002 ).…”