| Under the 1999 Canadian Environmental Protection Act (CEPA 1999), all chemicals listed on the Domestic Substances List (DSL) must be assessed in order to determine whether or not the substance is toxic, as defined in the Act. Chemicals are initially screened in terms of their persistence (P), bioaccumulative potential (B) and inherent toxicity (iT). The main purpose of this research project was to develop and evaluate a terrestrial food web bioaccumulation model to assess the validity of the CEPA bioaccumulation (B) screening criteria, which were derived solely from studies of aquatic organisms.; A steady-state bioaccumulation model was developed to predict chemical concentrations in soil-invertebrates and higher trophic level predators based on observed soil concentrations, site-specific soil properties, physical and physiological characteristics of modelled organisms and the physico-chemical properties of the modelled substances. The model was evaluated through comparisons of observed and predicted biota-soil accumulation factors (BSAFs) and biomagnification factors (BMFs) and through the use of Monte Carlo simulations to assess the sensitivity of model output to variation in key input parameters. (Abstract shortened by UMI.)... |
