PM19 Field-Based Effects Measures
Exhibit Hall
8:00 AM - Monday
(PM288) Using field experiments to determine critical body residue relationships and mode of action.
Salazar, M1, Salazar, S, 1 Applied Biomonitoring, Kirkland, WA, USA
ABSTRACT- There is a tendency among many of those working on aquatic toxicity problems to foster and perpetuate the myth that definitive answers can only be provided by laboratory experiments. Although these expectations might be applied to developing tissue residue effects data and identifying mode of action, the combination of "controlled" field experiments, tissue chemistry and biomarkers can be used in combination with more traditional approaches to provide important insights into what actually happens under environmentally realistic conditions. Appreciation of these field approaches has been enhanced by the development of ecotoxicology as a science and refinement of ecological risk assessment protocols which have placed equal emphasis on characterizing exposure and effects. Moreover, consensus-based, standardized protocols have been developed for a number of these field approaches. Recently, we have shown how caged bivalves have been used to predict critical copper body residues for effects on survival, growth, and reproduction using field data. This represents the first step in establishing more defined links between tissue chemistry and effects using field data. We have also shown that endocrine disruption, based on a vitellin assay in caged and indigenous bivalve populations, has been linked to chemicals associated with effluents from both municipal treatment facilities and pulp and paper mills. More importantly, it is possible to use this biomarker to distinguish between estrogenic and androgenic effects and establish mode of action even before the chemical associated with those effects has been identified. Relationships that have been established using ecological risk assessment-based monitoring demonstrate how field experiments help characterize exposure and effects and establish causality. Examples will be provided to demonstrate how this approach can be used to enhance traditional monitoring and assessment approaches.
Key words: critical body residue, field experiments, mode of action, ecological risk assessment