An Overview Of Aquatic Ecological Risk Assessment Methodologies

Abstract

A variety of methodologies are described that assess the risk of chemical exposure to aquatic life due to acute toxicity, chronic toxicity, bioaccumulation, or effects on communities. Risk assessment is basically comprised of hazard and exposure assessments, and this paper emphasizes methodology for the former. Although toxicity tests (both single species and microcosms) can be used to assess risks, most assessments rely on quantitative structure-activity relationships (QSARs) and similar techniques to fill data gaps in complex assessments. Equations are available for extrapolating toxicity from one taxonomic group to another, for predicting chronic toxicity from acute toxicity, for predicting biological activity (both toxicity and bioaccumulation) based on chemical structure or properties, and for predicting toxicity from multi-chemical exposure or time-varying chemical concentrations.