Abstract |
The TOX-SCREEN model, which was developed recently by the U.S. EPA Office for Toxic Substances, is a screening level, multimedia model designed to provide rapid assessment of the long-term tendency of toxic chemicals to accumulate in air, surface water, and soil. TOX-SCREEN simulates pollutant fate and transport by considering the release and dispersion of chemicals into the air, water, and soil; atmospheric deposition; volatilization; adsorption; leaching; and chemical-biological degradation. Transport of pollutants across media interfaces is specified by atmospheric deposition velocities, mass transfer coefficients, and mass loading parameters. The model assumes a generic positioning of surface water bodies and contaminated land areas with respect to atmospheric pollutant sources. In this study, an evaluation of TOX-SCREEN to determine its ability to perform reliable screening of chemicals was conducted. Evaluation included a review of the TOX-SCREEN processes and models relative to the current state-of-the-art methods, a comparison of TOX-SCREEN results with observed data and with predictions of other models, and a sensitivity analysis of selected input parameters. |