PARENT SESSION
PS1 - Wildlife Toxicology
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P038) Derivation of Wildlife Toxicity Reference Values for Ecological Soil Screening Levels (Eco-SSLs).
Burris, Janet*,1, Hoff, Dale2, Russom, Christine3, Charters, David4, Ells, Steve5, 1 Syracuse Research Corporation, Denver, CO2 US EPA Region 8, Denver, CO3 USEPA/ORD/NHEERL/Mid-Continent Ecology Division, Duluth, MN4 USEPA, Edison, NJ5 USEPA, Washington, DC
ABSTRACT- Wildlife Toxicity Reference Values were developed by the USEPA Superfund for the calculation of Ecological Soil Screening Levels (Eco-SSLs) protective of terrestrial wildlife. The wildlife Eco-SSL is the soil contaminant concentration where the Effect Dose (TRV) and Exposure Dose are equal (amount of contaminant in the diet that is taken up from soil). The TRV is defined as the dose above which ecologically relevant effects might occur to wildlife species following chronic dietary exposure and below which it is reasonably expected that effects will not occur. A four-step process was used to derive TRVs: 1) Literature search, 2) Literature review and data extraction, 3) Data evaluation, and 4) TRV derivation. This presentation examines the process and results of these steps for the determination of TRVs and subsequent Eco-SSLs for chromium, copper, cadmium, cobalt, antimony, RDX, DDT, dieldrin, selenium, and lead. The extracted toxicological data is classified by effect type for six classes of endpoints including mortality, reproduction, growth, biochemical, behavioral, and physiological. Each extracted result is assigned a data evaluation score ranging from 30 to 100 indicating the quality of the study. Studies with scores above 65 are then plotted by effect type and used to derive the wildlife TRV (Step 4) according to a pre-established selection and calculation hierarchy. The derivation process and results (both TRV and associated Eco-SSL) will be discussed for each contaminant.
Key words: Screening value, Soil, Wildlife, Superfund