Abstract |
The Terrestrial Ecosystem Exposure Assessment Model is a computer code that simulates toxic organic chemical exposures to wildlife. The approach was to build a code generally applicable to a diverse range of terrestrial ecosystems that could be parameterized to represent various ecosystem types. The initial focus, however, was on pesticide exposure to small and medium-size birds in agricultural settings. Using TEEAM, the environmental analyst can compute the probability of wildlife exposure in evaluating the registration or regulation of pesticides. The model, which consists of seven computational modules, simulates the environmental concentrations of pesticides in air, ephemeral surface ponds, soil, soil water and soil gas, plant roots and aboveground plant biomass, and animals in the food chain. These media serve as vectors for end-point species exposure to pesticides. The model computes both toxicant loadings to, and whole body concentrations in, the end-point species. To compute the probability of wildlife exposures to these environmental concentrations, the model is equipped with a Monte Carlo pre- and post-processing capability. The model documentation contains a discussion of model theory, code installation and execution, parameter guidance and programmer's-level model description. Also described is ATTEAM, a simplified analytical version of the food chain portion of the model. |