Research Programs: Contaminated Sediments
Research Areas: Predicting Effects

Contaminated Sediments

How to link residues to effects in aquatic and aquatic-dependent wildlife?

Background

Contaminants are transferred up the aquatic food web, creating a health risk for wildlife and humans. Click the photo for a larger image.
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For purposes of predicting toxicity for persistent bioaccumulative toxicants (PBTs), chemical doses are best expressed in terms of tissue residues because chemical residues in tissues integrate the contribution of doses received from all exposure pathways (i.e., from food, water, and sediment). To provide well-informed projections of risk, EPA must be able to assess the effects of chemical residues based upon an understanding of the dose-response relationship for the chemical and the wildlife of interest. For aquatic and aquatic-dependent wildlife, species sensitivities vary for a given chemical; and, in general, the dose-response relationships have similar shapes for organisms of the same family. To make decisions about how to remediate contaminated sediment sites, EPA needs to be able to assess the effects of chemical residues on the survival, growth, and reproductive success of aquatic and aquatic-dependent wildlife.

Problem

While the toxicological literature is extensive, there are considerable gaps in scientists' understanding of the linkages between chemical residues and biological effects in wildlife. Additionally, existing data are not available in a format useful to EPA.

Approach

The goals of EPA research in this area are the following

Assemble a consolidated database of up-to-date PCB residue-effects data for aquatic and aquatic-dependent species;
Evaluate the assembled data and clarify data gaps;
Make the database available and readily accessible to the EPA's Superfund program; and
Identify techniques and tools for a wider spectrum of PBTs and derivation of their residue-effects relationships.