| Abstract: | The Idaho National Engineering and Environmental Laboratory (INEEL) has implemented a phased approach to ecological risk assessment (ERA). The first step in this process is a screening-level ERA at each facility. Basic to this approach was the development of ecologically based screening levels (EBSLs), defined as concentrations of chemicals in soil (or other media) that are not expected to produce any adverse effects on selected ecological receptors under chronic exposure conditions (analogous to preliminary remediation goals or soil screening levels). EBSLs are calculated by rearrangement of standard exposure equations to solve for soil concentration when chemical intake rate is set at a developed toxicity reference value (TRV). A TRV is defined as a chronic dose that is likely to be without appreciable risk of deleterious effects. This definition was extended to define TRVs and ultimately EBSLs for the functional groups used in the INEEL screening-level ERAS. |
