BIOACCUMULATION AND FOOD-CHAIN ANALYSIS FOR EVALUATING ECOLOGICAL RISKS IN TERRESTRIAL AND WETLAND HABITATS: : AVAILABILITY-TRANSFER FACTORS (ATFs) IN 'SOIL → SOIL MACROINVERTEBRATE → AMPHIBIAN' FOOD CHAINS

摘要

As part of the ecological risk assessment process for terrestrial and wetland habitats, the evaluation of bioaccumulative chemicals of concern (BCCs) is frequently pursued through food-chain analysis with a subsequent comparison of daily doses to benchmark toxicity reference values, when available. Food-chain analysis has frequently been applied to the analysis of exposure to BCCs identified as chemicals of potential ecological concern (COPECs) in the ecological risk assessment process. Here, designed studies focused on wetland food-chains such as "hydric soil → soil macroinvertebrate → amphibian" and terrestrial food-chains such as "soil → plant → small mammal" illustrate an approach for the derivation and validation of trophic transfer factors for metals considered as COPECs such as cadmium, chromium, copper, lead, and zinc. The results clearly indicate that the transfer of chemicals between trophic levels is critical in the bioaccumulation process in wetland and terrestrial food-chains and is influenced by numerous interacting abiotic and biotic factors, including physicochemical properties of soil, and the role, if any, that the metal has in the receptor as a required trace element.