Anatomy of a Decision II: Potential Effects of Changes to Tier I Chemical Approaches in Canadian Disposal at Sea Program Sediment Assessment Protocols

摘要

The effects of possible changes to the Canadian 2-tiered assessment framework for dredged material based on outcomes ofrnthe 2006 Contaminated Dredged Material Management DecisionsWorkshop (CDMMD) are evaluated. Expanding on the “datarnmining” approach described in a previous paper, which focused solely on chemical lines of evidence, the efficacy of Tier 1rnapproaches (increases to the number of chemical analytes, use of mean hazard quotients, and the use of a screening bioassay) inrnpredicting toxicity are evaluated. Results suggest value in additional work to evaluate the following areas: 1) further expandingrnminimumchemical requirements, 2) usingmore advanced approaches for chemical interpretation, and 3) using a screening-levelrnbioassay (e.g., Canadian solid-phase photoluminescent bacteria test) to determine whether it would complement Tier 1rnchemistry as well as or better than the solvent-based MicrotoxTM test method evaluated in the present study. I